To point 1: Your argument leaves out forwards and centers who frequently shoot set shots during the game without jumping. Also, my point still stands: the form is similar enough because they can practice their elbow, release, spin, and arc mechanics - all similar to a jump shot.

2. Yes, but some players don't have hook shots at all. It's another shot you have to learn. Granted, with the amount of time NBA players spend practicing, they probably could learn another shot easily.

3. I agree with you here. These players should switch. But reputation and ego get in the way; it will take a player of influence to break through the "underhand free throw" barrier.