awww. Verryy cute! My first trail companion was a spotted saddle mare=]
As far as his confo, he is kind of bulky (a simple diet or more exerise will help drastically). & he has a slightly smaller head, but with a little weight loss, he will probably look more porportioned.
As for his movement, you might want to consider trimming his hind hoofs while keeping his front the same. This will allow for a smaller step in the back & a higher in the front. He would look even nicer if you held his head higher in the bridle, but I totally understand some horses just arent built to do so.
Gorgeous horse =]