Question 1 - no idea.
Question 2 - Not sure of the time. However, last time I installed a clear bra, I did it within three days of pickup at the performance center. Why wait and risk road damage? One thing I did when I ordered my 335 is I bought a roll of blue painters tape. The thick roll, like 4". I taped up the front end until I could get home and have a local installer put it on. Yes, it looked silly driving down the road, but I wasn't about to get any road damage.
Question 3 - The newer films are thinner and thinner. But yes, in general, it is more visible on a dark car. But look at it this way, rock chips are also more visible on a dark colored car. Be sure to not get lots of wax into the edges, unless you want a white line across your hood.
I would still say a clear bra is the way to go. I will never buy a car without one. And when I finally order my M3 (or M4, whatever), guarantee I will install a clear bra ASAP. Congrats, btw. Hope that helps.
Current - 2009 Carrera 4S
Current - 2010 128i convertible (wife's car)
Previous - 2009 M-sport 335i coupe
Previous - X5 3.0i with prem/sport
Previous - 2000 ///M roadster
Someone should invent a sarcasm font...