Assuming that they start adjacent.
quote:
I see it as you can take an AoO on the kobolds as long as the player uses the crossbow like a club, or if he has quickdraw, he'd be allowed a weapon change and then get both AoO's.
But, if he does not have the quickdraw feat, he'd be allowed, as I stated, to swing the crossbow (at the risk of damaging it, though) like a club.
Quickdraw is a free action. Free actions can only be taken on your turn, so no on switching weapons.
Using the crossbow as an improvised weapon is really a DMs call. If you do allow it it would certainly be at -4 penalty for improvised weapon. It would do 1d4 damage and I would consider the crossbow to be Fragile. There would also be a special consideration if it was loaded.