the priest in my campaign tried the elemental body IV spell (fire) but don't hit any monster - to low BAB. in his opinion, he could deliver touch attcks without any dmg by strenth but he wants to deliver the burn ability dmg.
is that right? what with sneak dmg? can he crit with a touch attack?
No, he cannot burn with a touch attack. Using that spell and the fire form is not combat efficient.