Here's what I see:
He has a nice neck which ties in well to a good shoulder with nice slope to it. The neck is of a good length to his body length (the ratio looks good) and he has a reasonable throatllatch. Being a Paint, it's not going to look as svelt as a throroughbred. He has a cute face!
His back is a good lenght and fairly flat. You will see some negative things about his conformation when you look at his hind quarters and how they tie into his back. Do you see that there is a slight "bump" just ahend of where his pelvis joins his back? It's in front of the LumboSacral joint. This , and the way that his pelvis is very flat (look at the angle from the point of his hip to the point of his buttock and you will see that it is closer to parallel to the ground than would be optimal) His croup is flat and you can see how his tail sits more on a flat surface than on a more vertical one? Flat croup. His stifle is very vertical and the thigh bone to hock is also extremely vertical. VEry post legged. Very! This means he cannot easily reach very far under himself, and may have something to do with why he trots quickly. Since he cannot fold his legs well and reach up and under himself, he cannot carry himself in balance while in movement. He relies more on falling forward and catching himself (the basic mechanics of walking or trotting) and this often means that momentum builds and he has no way to deal with this shift of forward momentum , except to speed up to try and maintain balance. Thus, the rushing forward syndrome.
His canon bones both front and rear are good and short and the hock is a little higher than the knee (good). Pasterns are shortish and good angle.
So, other than the flat croup and postlegged hind, he is sturdily built.