Well, just from what I can see in the pictures: You:
- Heels down and flexible consistently
- Good posture consistently
- Arms are held in a good position with bend at the elbows (just too high up)
- Hands too high, especially at a canter (they should be below the saddle horn)
- **Tight rein holds for a Western horse (Looks like you're riding contact) ESPECIALLY in a shank bit. If you hold the reins that tight he should be in a snaffle. A shank bit should be all or mostly neck-reined in.
- Lower leg to far forward/seat too far back (a bit of both)--There should be a straight line from you heels to your hips to you shoulders. You have the hips to shoulders right! Just line up the heels.
The Horse: Good
- Nice stride, very long and appears smooth.
- Has a nice hip and shoulder.
- Looks responsive to turns (hard to tell without watching the motion)
- Seems to have a supple back & neck
- Ears tell me he's paying attention most of the time and listening for cues. They're almost always tipped slightly backward, even at faster speeds, which says that he's paying attention to you rather than just what's in front of him and where he's going.
- Head kept high, especially at a canter. Loosening the rein and lowering your hands might help him to lower it.
- Front & hind legs look close to clipping at a trot. If they do, teaching him to pick himself up under his hindquarters can help increase the distance between the front & hind legs.
That's all I can really see with just pictures. A video would tell me a lot more