You are quite a stylish rider. Very classic, no frills or trendy posing, very workmanlike and correct. You have the perfect figure for riding - long legs that can really wrap around your horses barrel.
A couple tips to make your position even more supple.
Repostion your iron. Your stirrups are a great length and your irons are where they should be on the ball of you foot, but repostion your iron so that the outside branch leads the inside brach. The iron will now lay diagonally across your foot rather than straight across.
With your irons adjusted in this manner, your ankle will be more supple, and your heels will remain down and relaxed. This will help prevent your toes from sticking out and will keep your entire leg more elastic.
Your release is nice for a beginner to intermediate rider, but you have a strong enough postition to begin using an auto release. This will give your cute ony freedom to use his head and back even more and will keep you in control in the air and on landing.
An auto release separates the men from the boys.
Practice the auto by beginning in a two point position at a standstill. While in two point, spread your hands apart as far as you can while still keeping them level with your waist. Its easier said than done. If your position is the least bit weak or wobbly, you'll fall out of two point. When you can hold your two point with your hands spread wide, move up into the next gait until you can successfully canter round the ring in this manner. Once you are comfy in the flat, jump a small grid in this manner.
This wide hand position mimics what you may feel when you begin using an auto release. You cannot use your horses neck for support in an auto, so you are forced to rely on the strength of your base. An auto release will improve your balance and core greatly.
As for your pony...
Tight distances will get him to snap those knees up more, as will nice wide oxers. Right now he seems unchallenged by the small height, so hes just popping over the jumps without being super tight.
Lots of flat wirk will improve his rushing, Get his canter under control, be able to lengthn and shorten his stride on caommand the minute you ask it. If you can control his canter on the flat, you can control it over fences.
Lots of walk trot transitions help with jumping. They get a horse stepping under himself and carrying a much more collected canter.
If he still rushes the fence, then trot more jumps. All of the jumps in the pics you could jump form a trot. This way, the hrose is forced to wait, wait, wait, and you have more control ovre his speed than at the canter. Lots of half halts right before the fence.
If he is a spooky guy, I would introduce trot poles before and after the jump carefully. But if he is a solid citizen who isn't easily fazed, then I would right away put a few trot poles in front of a jump and a few closely set canter poles after. Teach him that after the jump he must collect himself and prepare for the next fence.