Nice post. Very good visuals.
My takeaways for someone who wants to hit a modern ATP style forehand is to 1) not let the racket hand get above shoulder height (there are exceptions to this, but I think it is best to avoid using those guys as models) 2) when the racket hand gets behind the body (not behind the line of the shoulders!) to extend the arm slightly (if you hit with a straight arm, extend it fully) and 3) (Very important!) "pat-the-dog" with the racket - meaning to close the racket face toward the ground rather than letting it flop back behind the shoulder like many of the WTA players.
I advise shadow swinging this a lot if you have access to a mirror. Do it in slow motion first, and then at full speed until it starts becoming natural. On the court, try to set up a camera to see if you're reverting back to your old habits.
I've been reworking my fh from something that looked WTA to something that looks more ATP recently. It felt weird at first, but now that I'm getting the feel for it, I really like it.