Very interesting breakdown of how throwing works. Funny how intuitive throwing is to humans, even though it’s such a complex process. I must add one thing, though. As someone who played baseball (and pitched) through high school, I think you’re giving a little too much credit to pitchers’ flexibility in the elastic energy part. While it’s hard for you to bend your arm back more than 90 degrees, I bet it’s the same for most pitchers. The arm muscles alone aren’t strong enough to store any more energy in the shoulder. In the pitching motion, you’re also using all that torque from the legs and torso to drive the elbow past the forearm, so quickly and forcefully that the shoulder doesn’t have time to say no. And when it does say no, and snaps back forward, is when the pitch is released.

This video and your explanation unlocked a few key things I would often think about but never had a good enough explanation of to grasp completely. The cues and terms used when a person is trying to guide you are more so how you should "feel" it. Do you think that a side arm arm slot would be more efficient at transferring and releasing the rotational force? When's the bat swing physics break down? I assume it's quite similar.

PSOAS Muscles are the KEY - - - - > > >

I would be a terrible pitcher

Armwrestling

Wrong. God taught Adam angular momentum. Our predecessors were always smarter than us. The evidence of the aforementioned is everywhere. Or at least nowadays the devil is struggling to hide this evidence any longer. You are very smart. Only your last statement is stupid. But nobody is that stupid on their own, they must be taught to be that stupid.