2) 53' is a good distance as I pitch at the lower level and see to many guys walking and pitching through the 6' "box", no pause or presentation, and the umps don't call illegally delivered after the ball lands. They call it a strike or ball just like a normally thrown pitch which is wrong.
3) to CRT, what kind of mat are you talking about for this pitchers area? I would worry about slipping or possibly tripping on it? I wear turfs, so slipping shouldn't be an issue, but for the guys who wear cleats still, it could hurt them.