I can't answer most of your questions but, as far as the DCT is concerned, I live in the Los Angeles area, and having to use a clutch in the traffic I see, would be a lot of work. With the DCT, in D mode, a simple tap of the throttle puts the car in a nice, non-jerky creep. About 5 mph. This works well in heavy traffic.
Just my opinion! Good Luck with the new M.