Hey kid first off GREAT for you to try combined training.
Don't take this personal, But I'm going to be VERY honest.
In the top picture;
First-The standing martingale is illegal equipment.
For you; Your elbows should be @ an apprx 90* angle,if you bring your arms together you should feel your ribs. Hands need to be 4" higher should never go below the top of the horses neck line. Wrists need to be perfectly straight, not crooked. When looking @ a rider from the side your elbow/wrist/rein should form a straight line. Yours is 2 completely different lines. Your stirrup,[guessing ?] down 4 holes. When sitting naturally with legs hanging down[no stirrup] the bottom part of your stirrup should be at your ankle bone. You are doing your flat work in a jumping saddle-not impossible but doesn't "help" to put you in a dressage position.
Jumping-Your feet need to have alot more weight in the stirrup and then pushed forward. What has happened here is you have gripped with your knee trying to stay on causing a pivot point. Your lower leg slips back and your upper body gets thrust to far forward. Looking from the side your foot should be directly against/along side your girth. Practice keeping more weight in your heel, leg pushed forward with toe in front of knee when looking down your leg. Then try to push your butt to the back of the saddle instead of going forward with your shoulders.
Stand on the ground, squat as in riding position, then push your butt backwards as you fold in half. Next try same position and lean forward with your shoulders and fold in half. The second way you take a step forward or fall. It works the same way on a horse. If you use your knee and develope a pivot point YOU WILL FALL OFF.
The amount of foot in the stirrup is ok, although MORE weight and try to keep them level with his sides so when you do turn your toes out it means go forward.
Horse-Good weight, very clean and tidy.
Again the standing martingale is illegal equipment except for Hunters. He has a nice bascule so he might not even need one.
I personally don't like standings for jumping. Should he have a bad landing he is restricted on his head/neck use and may not be able to recover because of it.
You are a very nice pair and with a little polishing will be a top notch competitor.
GREAT JOB !!