He has a pretty steep shoulder, which puts him heavy on the forehand. That may also be why he prefers the trot, more than the canter, because it's easier; the canter takes alot of impulsion from behind, and when you're already heavy on the frontend, transferring that energy to the rear, will be alot harder. With training, though, you can get him to move off the rear.
He does move fairly decently; a bit choppy, and doesn't track well, but as others have mentioned, he's not really being 'asked' to collect himself, so he probably isn't going to choose to. I quite like him, especially that crooked blaze and fiery little attitude he shows off at random intervals!