You complain of pain in your arm, yes? Maybe your technique is NOT flawed. Perhaps you have a neurological complaint? Have you checked that out? Really, any second-rate teacher could watch you playing a scale and determine if you are unconsciously applying tension to your exertion.
Well, I don't normally complain about it so much as it's relevant, so I mention it.
But we've done this. My arm pain was caused by playing the piano. I'm not mentally ill nor physically ill -in any way that, over the last 5 years, would have explained why I haven't made much, if any progress playing the piano.
I like House as much as the next man, but as much for his piano playing [which is, ironically given the context here, real] and superlative acting and the characterisation of objectivity.
"13"'s very pretty too

I don't see why anyone would copy the differentials though? That's pretty formulaic stuff and all made up. "What causes, crappy piano playing, a pain in the arm" Perhaps it's lupus?

But, you sound quite intelligent and self-aware
Yes, but this is a mistake. My piano playing sounds like I'm dumb, useless, stupid and moronic. I want to fix that - because I am. If writing English makes you sound intelligent, well, fine, but this intelligence is not helping me play the piano.
I have absolutely no clue. No idea how to play the piano. Really. This isn't through lack of information, lack of going to teachers nor a lack of trying though. Far from it.
I have no idea whether moving my arm / fingers / wrist / legs / anything else in one or more particular ways or another is correct or not. Nor whether imagining one thing or another will help. And it's not so much "is the way I play correct" more "are any of the numerous ways I might have tried in an effort to find out, correct?"
I know I don't do it properly primarily because of the sound, and also because it doesn't feel comfortable and, for my right arm, actually causes pain.
Also I know, because I realise I simply have no idea how to play.
That's to say, although I've read / watched and studied hundreds of videos, posts, books - if someone asked me how you were supposed to play the piano [or even something more specific], or asked what you would do to learn or asked me how you can improve at piano playing. I genuinely have no clue and no positive experience from which to give an answer.
If you said "practise makes you better" then, although that sounds correct, I have no experience of that. Practise makes no difference at all.
I might have some general, typically useless and empty, advice like "relax" or "practise"
I might dodge the question by suggesting someone else knows like "find a good teacher"
Or I might blather away some pseudo-Buddhist / jedi claptrap about "finding your own way. Don't try, do"
Or I might, as I did, post a link to what someone else says it is.
But in truth, I don't have the first clue how to play the piano. Not any aspect. I can't play one note. Oh, of course I can walk up to a piano and make it make a noise, but I have absolutely no idea how to play music on the piano...no idea how to play one note in a way that the resulting sound is under my control, let alone a number of notes to create music.
And I have no knowledge of anyone who does know. Least of all anyone that advertises themselves as a "piano teacher" and lives anywhere near me.
So, I'm either not intelligent enough, or being intelligent simply doesn't help.
Musically speaking? Well, there's no point at all where I've reached a stage with playing even just one note, or more, where discussing or trying any "interpretations" would make any logical sense. Because there's no correlation between how I might expect or want a piece of music to sound and how, when I move my body and touch the piano, the noise produced by the piano actually sounds.
That's to say, regard Lang lang sat with Barenboim
&feature=related here, [don't misinterpret me here, I'm not expecting to play as well as either, it's just an example of teaching] but what they are doing here is just a fantasy to me. e.g How Barenboim plays a short extract, perhaps just one chord in one way, and then in another. How Lang Lang plays one way and then changes the way he plays.
Now, perhaps to Marik or to someone else, one way is better than the other, but I'm not even close to playing the poor way. And not just with a piece that difficult [well, impossible for me to play] with any piece, or with just one note.
I'd love to be able to play in such a way that Barenboim could teach me something - but in truth, he's teaching someone who can already play the piano. Albeit, at the end of the teaching the student probably thinks they have only just learnt to play it

Someone like myself, as I've said to Marik, we aren't even in the same world.
I will probably never play the piano in that sense - certainly not before I discover how to physically play notes.
No one can say, "this is how you must depress the key to play the piano." That's absurd. The best we can say is
Heh, you say it's absurd but then go on to give your explanation

I've read / watched and tried many different ones. Including a few that are on this forum. "arm weight" - means nothing to me. No more than the explanations that say what sounds like [but might not be] the complete opposite, that you should hold your arms up [e.g see the fundamental action site]
I have no idea which were right, whether I was doing what they said correctly or not, nor, I guess, whether the crappy noise I make is the result of not doing it properly or just something else, like not imagining properly or something folks that like to split problems playing the piano into technique and musical would say is "musical"
If arm pain and a horrible noise could be down to using a correct technique, then I guess my technique could be correct. Except that, if good technique should give you the ability to, for example, play a note in a certain way, deliberately, then I can't see how I can have good technique without realising it and a tumour.
If you can, well, channel that to your fingers and just do it.
How? When I play it sounds rhythmically and dynamically sloppy....it sounds like, well, it sounds like I've never played the piano or the piece before.
It's not necessary to be a pianist to have worth in this life.
I don't want worth, whatever that is. I want to play the piano. If I didn't then I wouldn't be worrying about not being able to do it. I don't see how stopping playing, which would just mean I still couldn't play and never would, solves anything.
Now you say perhaps I'm talentless and never will play. If that was the case, fair enough, but I'm not sure, but you offer so many "perhaps" from stuff you've heard watching House

and so on, that you evidently don't know either.