I love your horse! Too cute!
There are a few things that stand out to me as things you might want to think about moving forward in your riding. I like your head and shoulders. You do a really good job keeping your shoulder blades pulled back jumping and flat and keeping your eyes up. You have a nice flat back over fences. It looks like you get quite stiff in your elbow joint and turn your hands flat like you're playing a piano. The stiffness in your elbow causes you to rock your upper body slightly to follow the motion of your horse, mostly in the canter. If you can think about keeping your thumbs up that will help with your whole arm position, turning your hands is why you can get them too close together. Your elbow joint should hang loose right below your shoulder. Try to "give" from your elbow joint as your horse's head moves and think about keeping your upper body still. This will help you stay deeper in the saddle. To work on your arms you can ride with a crop held on top of your thumbs or like behind your back coming in front of your elbows to pull them back.
As far as your legs go, I'd like to see you sink into your heels more and wrap your whole leg around your horse. One thing I think about to do this is the idea that I'm going to wrap my heels around my horse's stomach and touch them together. And in general over fences you tend to get your upper body a smidge ahead and not bend in your hips. Once you get more confident in your jumping you'll probably find that you can find a more natural position in which you fold more at the hip and go with your horse's motion.
I hope that helped, you're definitely on the right track, keep up the good work!