Rather than having pretedetermined class structures hold you back, you can acquire class features the same way you do feats. Your effective class level with a class feature is dependent upon your generic class.
If you have the correct class twice, your effective level is equal to your character level.
If you have only half the right class, your effective level is 3/4 your character level.
IF you don't have the right class at all, your effective level is 1/2 your character level.
Warrior: Barbarian, duelist, eldritch knight, fighter, monk, paladin, stalwart defender.
Rogue: Assassin, gunslinger, ranger, rogue, shadowdancer.
Mage: Alchemist, bard, cleric, dragon disciple, druid, inquisitor, loremaster, magus, mystic theurge, oracle, sorcerer, summoner, witch, wizard.
Unless noted otherwise, your effective level with a base class ability is equal to your full level and your effective level with a prestige class ability is equal to half your level.
The experience cost of a class feature is equal to the level at which it is acquired in the class + the number of class features from that class before that one which you do not have (if any). If the features are particularly strong or weak, they may be half or double this much (GM determination).
A-E
Acrobatic Charge (duelist talent): They must meet all the requirements to become a duelist and acquire Improved Reaction, Grace and Enhanced Mobility first.
Animal Companion (druid spell): You gain an animal companion as a 2nd level druid. Each time you take this, it increases your effective level by 2, up to a maximum equal to your total HD.
Angel of Death (assassin advanced talent): You must have Death Attack and True Death. Treat your rogue level as your assassin level for this ability.
Armor Training (fighter): A warrior can acquire a rage power as a combat feat. Their effective Fighter level with it is 4. Each time it is taken, their effective fighter level increases by 4. This includes Armor Mastery at effective 20th.
Athleticism (any): You must have Climb and Swim as class skills. You gain a Climb speed and Swim speed equal to half your base speed (rounded up). In addition, you are always treated as having a running head start and can jump four times farther than your Acrobatics check would normally indicate.
Aura of Courage (paladin feat): You must have Bravery.
Aura of Fear (antipaladin feat): You must have Bravery.
Bardic Knowledge (bard spell): Your mage level is your bard level.
Bardic Performance (bard spell): At 1st level you start with two types of performances from the following list:
countersong, distraction, fascinate, inspire courage. Each time you acquire this ability, you gain two more types of performances and add additional performance options you can select based on how many times they have this ability:
1st: Countersong, distraction, fascinate, inspire courage +2.
2nd: Add Inspire Competence +2 and Suggestion to the list.
3rd: Add Inspire Courage +4, Dirge of Doom, and Inspire Greatness to the list.
4th: Add Inspire Competence +4, Soothing Performance, and Frightening Tune to the list.
5th: Add Inspire Courage +6, Inspire Heroics, and Mass Suggestion to the list.
6th: Add Inspire Competence +6, Mass Suggestion, and Deadly Performance to the list.
Bravery (fighter feat): You gain a +2 bonus to saving throws against fear and immunity to fear effects. This bonus increases by +1 for every 5 levels you possess.
Channel Energy (cleric spell): You gain channel energy as a 2nd level cleric. Each time you take this, it increases your effective level by 2, up to a maximum equal to your total HD.
Crippling Critical (duelist feat or talent): You must meet all the requirements to become a duelist. You learn only one of the possible conditions each time this is selected (though you can create only 1 of them at a time).
Damage Reduction (barbarian feat): Strength and Constitution must be your highest two ability scores in order to select this feat. You gain Damage Reduction 2/-. You can take this feat multiple times, increase this DR by 2 each time you take it. You cannot increase this DR above your HD.
Darkvision (shadowdancer talent): You must meet all the requirements to become a shadowdancer:
http://www.d20pfsrd.com/classe...er#TOC-Darkvision-Ex-
Death Attack (assassin advanced talent): Your effective assassin level is equal to half your rogue level.
Deflect Arrows (duelist feat or talent): You must meet all the requirements to become a duelist and acquire Improved Reaction and Parry first.
Domain (cleric spell): You acquire a single cleric domain as a 4th level cleric. This includes gaining all the spells and domain powers of the domain. Each time you take this spell you can select a new domain or increase your effective level by 4 up to a maximum equal to your actual HD.
Enhanced Arrows (arcane archer spell): You must meet all the requirements to become an arcane archer to acquire these abilities. Your effective arcane archer level is equal to 2. They increase their effective arcane archer level by two and gain all the normal arcane archer upgrades to arrows associated with those levels (
imbue arrows, elemental arrows, seeker arrow, distance arrows, phase arrow, elemental burst arrow, hail of arrows, aligned arrow, arrow of death).
Enhanced Mobility (duelist feat or talent): You must meet all the requirements to become a duelist.
Evasion (monk feat or rogue talent): A rogue can select this feature as a rogue talent. They can select Improved Evasion as an advanced rogue talent.
Evasion, Improved (monk advanced feat or rogue advanced talent): You must have Evasion.
F-J
Fast Movement (barbarian): A warrior can acquire this class feature as a combat feat. It grants you a +5 foot racial bonus to your base speed. It can be stacked.
Fast Movement (monk): A rogue can acquire this class feature as a rogue talent. It grants you a +10 foot enhancement bonus to your racial base speed. It can be stacked.
Grace (duelist): A rogue can acquire this class feature as a rogue talent. They must meet all the requirements to become a duelist.
Hidden Weapons (assassin): A rogue can select this feature as a rogue talent using half their rogue level as their effective assassin level.
Hide in Plain Sight (shadowdancer): A rogue can acquire this class feature as an advanced rogue talent. They must meet all the requirements to become a shadowdancer.
Impromptu Sneak Attack (arcane trickster): A rogue can select this feature as a rogue talent using half their rogue level as their effective arcane trickster level.
Improved Reaction +4 (duelist): A rogue or warrior can acquire this class feature as a rogue talent or combat feat. They must meet all the requirements to become a duelist.
Invisible Thief (arcane trickster): A rogue can select this feature as an advanced rogue talent using half their rogue level as their effective arcane trickster level. They must first select Major Magic (Vanish) rogue talent.
Jack of All Trades (bard): A rogue can select this feature as an advanced rogue talent. Their effective bard level is equal to their rogue level + half all their other class levels.
K-O
Lore (loremaster): A mage can acquire Lore, Greater Lore and True Lore each instead of a spell or bonus feat provided that they meet the requirements to become a Loremaster.
Lore Master (bard): A mage can acquire this class feature in place of a spell. They must first have Bardic Knowledge and be 5th level. Taking 20 on a knowledge check can be used once per day per 5 mage levels you possess.
Loremaster Secret (loremaster): A mage can acquire a secret instead of a spell or bonus feat. They must meet the requirements to become a Loremaster and have the Lore ability to acquire up to 2 secrets, Greater Lore to acquire up to 4 and True Lore to acquire up to 6.
Magus Arcana (magus): A mage can acquire one of these as a bonus feat provided that they meet the prerequisites.
Mettle (n/a): A warrior or mage can select this in place of a combat feat or spell.
Nature Sense (druid): Anyone with Knowledge (Nature) and Survival as class skills can acquire this class feature in place of a combat feat, rogue talent or spell. It grants you a bonus to Knowledge (nature) and Survival checks equal to half your character level (minimum +1). It also grants you the benefits of
purify food and drink and
detect poison on any substance you consume or taste as if you had cast these cantrips. It only applies upon tasting the food or substance thus making you aware if it's poison and also dispelling the poison for you and only you. Your caster level with these effects is equal to your character level.
No Retreat (duelist): A rogue or warrior can acquire this class feature as a rogue talent or combat feat. They must meet all the requirements to become a duelist and acquire Improved Reaction and Enhanced Mobility first.
P-T
Parry (duelist): A rogue or warrior can acquire this class feature as a rogue talent or combat feat. They must meet all the requirements to become a duelist and acquire the Improved Reaction feature first.
Precise Strike (duelist): A rogue or warrior can acquire this class feature as a rogue talent or combat feat. Their effective duelist level is equal to their character level. They must meet all the requirements to become a duelist.
Quiet Death (assassin): A rogue can select this feature as an advanced rogue talent using half their rogue level as their effective assassin level. They must first select Death Attack.
Rage (barbarian): A warrior can acquire this class feature as a combat feat. They must meet all the requirements to become a barbarian and have the Endurance feat. You can take this a second time at 7th level to improve it to Greater Rage, a third time at 13th level to improve it to Tireless Rage and a fourth time at 19th level to improve it to Mighty Rage.
Rage Power (barbarian): A warrior can acquire a rage power as a combat feat.
Ranged Legerdemain (arcane trickster): A rogue can select this feature as a rogue talent using half their rogue level as their effective arcane trickster level. They must first acquire Minor Magic (Mage Hand) before this can be selected.
Resist Nature's Lure (druid): Anyone with Survival as a class skill can acquire this class feature in place of a combat feat, rogue talent or spell. If you have at least 5 ranks in Knowledge (nature) and Survival, you can take this a second time to gain Venom Immunity as a druid.
Riposte (duelist): A rogue can acquire this class feature as a rogue talent. They must meet all the requirements to become a duelist and acquire Improved Reaction, Parry and Enhanced Mobility first.
Shadow Call (shadowdancer): A rogue can acquire this class feature as an advanced rogue talent. They must meet all the requirements to become a shadowdancer and have Shadow Illusion.
http://www.d20pfsrd.com/classe...r#TOC-Shadow-Call-Sp-
Shadow Illusion (shadowdancer): A rogue can acquire this class feature as a rogue talent. They must meet all the requirements to become a shadowdancer and have Minor Magic (any illusion spell or prestidigitation).
http://www.d20pfsrd.com/classe...C-Shadow-Illusion-Sp-
Shadow Jump (shadowdancer): A rogue can acquire this class feature as a rogue talent. They must meet all the requirements to become a shadowdancer.
http://www.d20pfsrd.com/classe...r#TOC-Shadow-Jump-Su-
Shadow Master (shadowdancer): A rogue can acquire this class feature as an advanced rogue talent. They must meet all the requirements to become a shadowdancer and have Shadow Call and Shadow Illusion. You gain only DR2/- while in dimly lit areas. While in total darkness or magical darkness, you increase this to DR5/- and gain a +1 luck bonus to all saving throws. This talent can be selected up to twice, doubling its bonuses.
Shadow Power (shadowdancer): A rogue can acquire this class feature as an advanced rogue talent. They must meet all the requirements to become a shadowdancer and have Shadow Call and Shadow Illusion.
http://www.d20pfsrd.com/classe...#TOC-Shadow-Power-Sp-
Sneak Attack +2d6 (rogue): A rogue can acquire this class feature as a rogue talent. They must have at least 1 rank in Stealth plus 4 additional ranks per time it is selected after the first. Each time it is selected it stacks: (1, 5, 9, 13, 17, etc.)
Spell Combat (magus): A mage can acquire this ability as a bonus feat.
Spell Combat, Ranged (magus): A mage can acquire this ability as a bonus feat. It functions as Spell Combat but it mimics Rapid Shot instead of Two-Weapon Fighting and they do not need a free hand to cast a spell so long as they are wielding only a ranged weapon.
Spell Critical (eldritch knight): A mage can select this feature instead of a feat or spell. They must first meet all the requirements to become an Eldritch Knight.
Spell Strike (magus): A mage can acquire this ability as a bonus feat. They can use with any weapon that they are proficient with and only within 1 range increment (if ranged).
Summon Shadow (shadowdancer): A rogue can acquire this class feature as an advanced rogue talent. They must meet all the requirements to become a shadowdancer and have Shadow Illusion.
http://www.d20pfsrd.com/classe...TOC-Summon-Shadow-Su-
(requires Shadow Illusion)
Surprise Spells (arcane trickster): A rogue can select this feature as an advanced rogue talent using half their rogue level as their effective arcane trickster level. They must first select Tricky Spells.
Swift Death (assassin): A rogue can select this feature as an advanced rogue talent using half their rogue level as their effective assassin level. They must first select Death Attack and Quiet Death.
Trap Sense (barbarian/rogue): A rogue or warrior can acquire this class feature as a rogue talent or combat feat. You must have Dex or Wis 13 to acquire it. It grants you a +4 dodge bonus to AC and +4 bonus to Reflex saves against traps. It can be stacked once per 10 levels you possess.
Tricky Spells (arcane trickster): This ability is replaced by Sudden Metamagic effects. A rogue with Minor Magic can select the following metamagic feats in place of a rogue talent: Bouncing Spell, Dazing Spell, Disruptive Spell, Ectoplasmic Spell, Shadow Grasp, Silent Spell, Still Spell, Tenebrous Spell, Umbral Spell.
True Death (assassin): A rogue can select this feature as an advanced rogue talent using half their rogue level as their effective assassin level.
U-Z
Uncanny Dodge (barbarian/rogue): A rogue or warrior can acquire this class feature as a rogue talent or combat feat. You must have Dex or Wis 13 to acquire it. If you have Dex or Wis 15, you can take it a second time to function as Improved Uncanny Dodge.
Versatile Performance (bard): A mage or rogue can acquire this class feature in place of a spell.
Weapon Training (fighter): A warrior can acquire a rage power as a combat feat. Their effective Fighter level with it is 4. Each time it is taken, their effective fighter level increases by 4. This includes Weapon Mastery at effective 20th.
Well-Versed (bard): A mage can acquire this class feature in place of a spell.
Wild Empathy (druid/ranger): Anyone with Handle Animal and Survival as class skills can acquire this class feature in place of a combat feat, rogue talent or spell. It grants you a bonus to Handle Animal and Ride checks equal to half your character level (minimum +1) and allows you to interact with animals the same way you can with humanoids. You can demoralize them or change their attitudes with the Handle Beast skill the same way humanoids would do so with the Intimidate or Diplomacy skills against other humanoids.
Wild Shape (druid): Anyone with Knowledge (nature) and Survival as class skills can acquire this class feature in place of a combat feat, rogue talent or spell. You gain all the effects and uses per day as a 4th level Druid (max equal to your actual character level). This can be taken multiple times each time adding 4 to your effective druid level. This also grants the Thousand Faces and Timeless Body abilities at the appropriate levels.
Woodland Stride (druid): Anyone with Survival as a class skill can acquire this in place of a combat feat, rogue talent or spell. In addition, you gain Trackless Step if you have at least 3 ranks in Survival.