I don't know anything about gaited horses, so I may be wrong here, but his backend is shocking! He has no muscle over his hindquarters, and his rump should be in line with his hocks, which it isnt. He should dip slightly over his flank, but he doesnt, which could suggest back problems? His front legs look pretty good, although he is slightly ove at the knee, but it isnt a major problem.
The reason for him standing so funny could be due to back problem too. If this was my horse, I would get a chiro to look at him.
As I said, I know nothing about gaited horses, but im assuming they should be similar conformed to other horses. Im sorry if im wrong! (: