Is your bunn eating his hay yet? If not, I would suggest your vet anesthetize him and take a very, very good, thorough look at his back teeth. He might have a misalignment or some other problem that makes it difficult for him to chew hay properly. Especially if he already has trouble with his incisors which could throw off the way the molars grind against each other. Watch him carefully when he eats things that are similar in shape to hay to see if he looks like he takes extra time trying to maneuver things in his mouth.
And as far as his incisors, if they are truly misaligned, a good rabbit vet should be able to shape the teeth in a manner that would help work the alignment back in place, rather than just trim/clip them. If they angle the bevel properly, it will eventually get things back to normal after a few shaping sessions.
And yes, generally misaligned incisors is a genetic thing, but I've seen adults develop this after an accident or even from a severe case of chronic, consistent yanking/pulling too hard on the cage bars.
Good luck!