hi shootin
i tend to agree with you in what you say, when you look at the top plays there spine angle is the same from start to finnish and its the the bigest diffrence from the rest of us handicap player the tend to move about a bit,
its why monty looks so smooth and slow with a driver, like you said he stands tall and swings around and has one of the best finnishs in golf, he always swing to finnish even on a 50% swing.
if you control your right knee and dont lock it but keep it flexed on the backswing the hip turn take care of themself. you cant over turn your hips if your knees still felxed but you can if your right leg locks on the backswing.
bill