I can't see the vid because I'm at work so my critique will be based on the photos only, sorry.
I love your release, very soft, giving and appropriate for a greenie. I also love your horse's expression, clear willingness and how round he is over the fences.
But I would *highly* recommend that you go back to grids and gymnastics, and not attempt single fences until a little further on. You can do some research online about how to build appropriate grids and how to add difficulty and complexity as your horse progresses.
I say this for a couple of reasons - If you don't have a really good eye for pace and distance, there's way too much chance of getting a young horse in wrong and either scaring them or reinforcing the wrong things. A gymnastic sets the horse up for sucess, there's no getting in wrong.
Two, your position is not as solid as it needs to be to school single fences. The second photo is better, but it still looks as if your leg has slipped back. A grid or gymanstic gives you the chance to think about your position because you're not worrying about the distance or anticipating the fence and getting out of the saddle early.
Three, your horse has not learned to use his front end well yet. If I hadn't read your post and understood where you were in his training, I'd be pretty horrified by that first photo with his forearm and knee pointed down. He's much better with his front end in second photo - not great, but better. However, I truly believe it's because he doesn't know how to use himself yet. I think he's athletic enough and willing enough to improve his form.
When you do go back to single fences, do always use ground lines, and do alway roll the ground line out from the base of the fence to help hiim see his distance and to give him a little more time to rotate his shoulder and bring his knees up.
I will try to find some exercises for you on building gymnastics.
And I will try to look the vid from home.