Lookin' good! I thought I was watching my own training session. We're just about in the same place. I use walk-trot transitions about the same way as you and also do leg yield to get him into the outside rein. Works great! Your horse looks nice and relaxed. He's mostly connected over his back and reaching into nice forgiving contact up front. It's so nice to see others not pulling on their horse's face. You obviously understand the true goals of dressage.
Like wildberry said, your shoulders are a tad slouched, but nothing that screams hunchback or anything. I like your upper body in the canter. You absorb his motion nicely and appear to be nice and still.
Your horse could stand to have a little more impulsion at the trot. You already know to transition between gaits. I'm thinking next step is to transition within gaits. Working trot to trot lengthening transitions would be a good next step to developing his impulsion and test his balance a little more. He looks like he's ready for it.
You just have to see your distance...you don't have to like it.