I see nothing wrong with his feet , at all. The video is of a poor resolution, so there is a bit of "jolting" action to it that makes the horse look like it moves wierd. To me, and I am not expert, he moves just fine.
In fact, I think he's rather well built and I like him a lot.
What I do see, however, is a horse with a very hard mouth and mind. It looks like he's been ridden by people without very soft hands for much of his life and he holds himself in a very braced and defensive manner. The boy was jerking on his mouth and even at a standstill had the reins (to a curb bit!) pulled tight. Even the man who rode with a chest rope was jerking on him and gave the body signals to stop AFTER a jerk on the rope, instead of cueing first with his body, then the rope.
I get the feeling that he has been being a good boy and putting up for many years. If you were willing to kind of restart him and work on building some softness in him, I believe he would be a good horse for a beg. low intermediate rider.
I like him!