Is it required for a cadet to view the ground handling video if they are in civilian clothes washing a non CAP plane if they are not moving it at all?
Probably not. But, would it hurt? It's not a bad idea. More traiing IMO is always better than less.
No the video is for for CAP while you are in uniform and functioning as a CAP member using their airplane. Although I agree it wouldn't hurt to view if you are on any flight line.