Replying to My form for rails needs help

I made a crappy thread at the beginning of the season about how to hit rails from the side (used the first clil). 3 months of skiing later I have a few more questions. Most of them apply to my take off. I know that i ski like a boner so don't yell at me about that, but when I take off, my arms always flail behind my back for some reason. I never see anybody else do it. I tried fixing it one day but it felt really awkward. Also, i have a really hard time getting onto rails with really small kickers when others seem to have a lot less trouble. Yes I actually use shin pressure and bend my knees for that. When i ollie, I get put in the backseat and i slip out. I can't seem to get my body forward again. Or i just clip my tips cause I can't get the skis over. Then when I do get over the rail. I come off on the other side early a lot. This is frustrating for when I want to try a front 2 and have a hard time pedaling since i am on my heels. Finally, on skinnier rails I can't seem to really keep my skis from reverting back to straight and cause me to nut. I luckily i never have nutted but my only hand rail hits have me pedaling back to straight instantly, and that isn't on purpose. I have boots that are too big and I am getting new ones next year just incase that would cause issues. I'm glad that I can finally hit most rails urban style but I feel like I hit a wall and I have been learning front 2's on flat and easy rails and plan on getting back 2's early next year. Here is a video on the before and after with some examples of what I am talking about.
https://www.newschoolers.com/videos/watch/867298/trim-69BC67B8-F2AA-44DB-A30B-6693E2D06CF8-MOV