Hold the club just above the ground and at Fix now change the degree of bend in your Right Elbow (from more bent to lil' bent to straight) notice the travel of the clubhead AND the resulting travel of the face. I think the degree of bend in the right elbow must be compliant with the selected hinging. It seems to me that with Horizontal Hinging the Right Elbow reaches its in-line condition quicker in Follow Through than with Angled and Vertical Hinging.
I think #3 is done at Full Lever Extension when the Accumulator is zeroed out.