Ah he is beautiful! He has the kindest eyes and such an honest face, I am jealous lol!!
I don't see anything really obviously wrong conformation-wise, but like everyone else says he is a little downhill and looks heavy in your hand, like he's using your contact to balance himself with ... I have the same problem with my mare and she consequently doesnt have very good balance so I would suggest lunging or riding (or both) with side reins or a bungee - which is what im using at the mo - to get his head up, using his back better and improve his balance.
But you look like a great pair and he looks a lovley horse :)
He is gorgeous :)
Like the others have said he looks pretty downhill, you could probably solve that by leaning back a bit more and doing loads of downward transitions to get the weight back on the hindlegs :)