Hahah "I don't want him to snap at me for criticizing his ability to accept criticism"
I like that. :) They're right now - you don't have to feel bad for not helping, if the person you're trying to help won't accept it anyway and just attacks you for it. He'll fail for a while, probably pick up some bad habits along the way, the criticisms will pile up steadily, but if he's got potential like you say and he cares enough to keep writing, he'll be alright.