It's really not that big of a deal, he's not used to you, oh well, he bit, it happens. AFTER a few weeks, so he has time to unstress from the move and calm down, handle him alot (not during or after feeding). Until then, just feed him in his cage. It's not that big of a deal, he's not going to form a habbit in 3 weeks that will last his whole life. I personally DO feed my snakes out of their cages, but not for a tame factor, just for the clean up the mess factor.
Also, GET HIM OFF THE SAND. Use news paper, or best of all (IMO), paper towels. I keep all of my snakes on paper towels, even the big ones. It's soft, absorbent, and easy to replace. News paper does work well though.
Don't worry about that bite. I rarely get bit, but it does happen! I have a super tame 7 footer that tagged my girlfriend the other day, for no apperent reason.
Good luck