Lets see, there's lots of opinions you'll get here, I'll try to answer best as I can.
We are 2 time Sprinter owners, and the second one will be our last.
Answers:
A: our 2008 , very good. Our 2013, the body and sheet metal fits, bad. Otherwise a terribly misaligned from Mercedes, front end when new chewed up our front tires so they needed replacement by 10k miles.
B: dealer service varies a lot depending where you are. We have to drive 40 miles to either a Freightliner or MB dealer to get anything done, and we're in a metro area with 1 million + population. Some places 100 miles or more
C: to us, yes. Poor skills to do it here
D & E: no, if there is a next one, it'll probably be a Ford Transit based unit or a MUCH lesser chance, a Ram ProMaster. Way, way, way more service locations on either of those