You did almost good job
OK, I'm joking, your thread is quite good, but there are some mistakes. First at all, you have to write that you are talking about biomechanics of serves. As example, pronation of forearm is one of the most important sources of energy at topspin forehands and (supination) at topspin backhands (30-40%!).
Also, this image is wrong:
Upper arm and shoulders should be colinear. The straight line along upper arm and shoulders is an axis of rotation of forearm. This axis should be tilted at ca 45 degrees at serves. Due to educational reasons, you should make corrections in the picture above and add an image with tilted axis.