He's a pretty sturdy- looking boy, I think that once you get some muscle on him and he's healthier (and not in his winter fuzzies) he will be a good looking boy!
He seems to have some pretty typical qh conformation. Do you know what his breeding is, by chance? He has very short pasterns that are pretty post-y, with very round hocks and nice short canon bones. His front legs look nice and straight to me, and I'm not sure if his back legs are sickle hocked or just straight... You'll have to wait for a more knowledgeable user to tell you more about that
He has a nice deep girth, with what looks to me like a good-sized rib cage.
I actually like his shoulder, it's a good size and balanced with the rest of his body pretty well, although it is kind of steep. He has high withers and is downhill, with a nice length of back and a high, steep croup with a possibly high-ish tail set. His neck may be a tad short and MAYBE set on a bit low, bit it's a well-shaped neck, although it could use some muscling- I like it!
PLUS he has a cute little doll face, although he looks like he's saying 'seriously, mom, I'd rather nap...' in this picture, lol.
I'd love to see some progress pictures as you work with him, I think with muscles and a good solid top line he'll be handsome as heck. I'm betting that he has a great stop on him, do you think reining is in his future?