Who is considered Right Worshipful?
Not sure I understand what you're asking, but DDGM's do hold the honorific of "Right Worshipful" during their term of office.
That is the way I was taught, dropping the Wardens to Warden if you serve as one.
Only if the DDGM is in charge of the Lodge at that time. Otherwise, the WM is in charge & should properly be addressed first.