You look fairly good, actually, nothing horribly wrong, just small things. You are behind in a couple of those shots, so I would really focus on staying with the motion. Also, like every riding instructor has screamed a thousand times, heels down! Really sink your weight into your heels, it will help with everything. For the release, don't think of reaching for the neck or the mane, think of releasing your horse's mouth. In theory, your arm should create a direct line from your elbow, through the reins to the horse's mouth. I like to think of jumping as a big canter stride, instead of throwing your hands up there, give to your horse the same way you would at the canter, but exaggerated. If you have the balance to sink your weight in your heels and not touch the mane, that is ideal. I think your shoulders are slightly hunched, getting your heels down will help. Good luck!
The basest horn of his hoof is more musical than the pipe of Hermes.
He's of the color of the nutmeg and of the heart of the ginger.
His neigh is like the bidding of a monarch,
And his countenance enforces homage.
- William Shakespeare