sounds perfectly normal for a beginner TBH. You simply don't have technique sorted and don't have consistency to what technique you do have. so not only do you have bad habits. you don't even actually know what they are yet. Ideally you want to get to the point you're not having to think about anything and muscle memory takes over. eventually with most of that BAD technique will naturally be gone.
practice makes perfect n aw that.
see my answer to point 1 above..
what will help with this is good balance and body positioning in the first place. - Don't worry though. this will come by simply riding more. low speed riding helps more than high speed.
What will also help is pre-planning and visualisation. ie. properly thinking about what are you attempting to do and how exactly you are going to go about achieving it?
at the moment you're just rocking up pedalling at the ramp and hoping for the best. am I right? (it's ok. I know I am

)
You're trying to teach yourself FAR TOO MUCH at the same time, constantly building new ramps with different lengths, heights, radius' etc. is simply overloading your learning capability... and TBH it's doing my head in trying to keep up offering advice when you won't actually stick at learning one thing before moving on to something new. Especially when you haven't really listened to the advice I've given previously. It's great you're doing this. But try to ignore all the praise you're getting from folk who don't actually have a clue what they're praising. VLOGing is IMO actually detrimental to your progression. You're spending way more time and effort building "entertaining" ramps for content than you're putting in to actually jumping.
eg. You shouldn't be
pulling at all. like I told you pages back.
Go back to basics. planning, aproach speed, good positioning. looking ahead etc. pedalling towards the ramp with a fixed idea of where you'll stop pedalling and the body position you need to adopt , where you'll be looking and when you'll need to apply preload. How this will affect your take off, trajectory and body positioning, when you'll need to spot your landing, when and how you'll land and how you'll absorb the landing to be as smooth as possible.
don't worry about going backwards. it can be a kinda one step forwards, two steps back dynamic to get there. Especially at our age.
Now don't take what I'm about to say too harshly
You've built yourself a fun box!
You didn't even know its name. Nevermind what a fun box is actually for.
it's a skate park jump designed intentionally with a steep lip to give riders the oportunity to get good height, a flat top and longer mellower landing to allow riders to practice tricks in relative safety. Thing is, you've not advanced enough for a fun box to be all that much use to you (yet). and TBH you should ideally be on a fully rigid bike (BMX) or at least a hardtail rather than a 50lb 150mm travel Emtb to get the most from it.