I can give you a critique just based on the single photo you posted. Normally I will only take the time if the poster has front and rear views as well, because with the side profile, it really limits how much we can critique.
I will post my critique tho for you, and I will be using the most up to date picture you added
Neck length should be one third of the horses total length. His neck is a little bit to short in proportion to the rest of his body, which will make it a little bit less flexible. You will want a good head and neck length for balance and proportion. The head and neck counterbalance what the hind end is doing. Shorter necks are sometimes also associated with a more upright shoulder. The horse is overall very well proportioned which is nice to see.
The photo does not seem to be level. It looks like the horse is standing downhill, so its hard to tell if he is build downhill or relatively level? I would like to say he is level, but can't tell by that photo.
This horse a fairly steep shoulder, making feel he must have a shorter stride which will affect smoothness. Its also factor in degree of concussion to which his leg bones and joints are subject to. The front legs will be more affected, because the front carries more weight.
The angle of the pastern, and the angle of the foot created a straight line from top to bottom which is what you want to see. I do see something that concerns me however, and its the slope of the pasterns. He has longer pasterns as well which makes them weaker and more prone to breakdown. You don't want to see an angle that is less than 45 degrees which is the case in the hind end.
His stifle is lower set and is level with the elbow in the front legs. A lower stifle goes hand in hand with a medium short gaskin which gives you more power in the hind end.
Can't take a look at the hocks, because pictures were not provided tho from the photos provided, he doesnt seem to have suffered any injuries.
If you provide more photos, we can take a look at a few more things.