1.) What do you guys teach to get a rearward movement at the beginning of the pitch?
2.) With the rules changing allowing for a step backward off the pitching rubber, how can I incorporate this movement into my pitchers motion?
I think you're referring to the load. It can be as individual as her hair style. All that really matters is that there is a negative move leading the explosion.... picture a boxer punching without any negative arm move...its called a jab. No damage, and is primarily used as a set up punch. But when he's looking to land solid, there will be a draw back and launch.
Pitching, hitting, and throwing are no different.
A pitchers negative move in her arm needs to happen as her body is driving forward, creating what we call "overlap."
Some variations of this are called single pump, double pump, hide the ball, rock the baby etc.... all are ok, however some have more/different advantages than others.