If you're getting a hatchling, I'd say don't hook train, just use gloves if it's snappy. Get to know the snake and its feeding response, then determine whether hook training is appropriate. Although I suppose it really couldn't hurt.
I'm not convinced feeding out of the enclosure would help much at all. They're such aggressive feeders, they see a rat-sized, warm, moving object (your hand) and they forget where they are or what they were doing.