2) Yes, but it voids warranty. There is an option to get a HDD as large as 250GB when ordering.
5) Not that I am aware of. Keep in mind that this is not a particularly powerful system by today's standards. Performance on many applications may not be what you would like.,
6) Unknown. I would think you'd need to evaluate MTBF for each individual components, namely the LCD, HDD & optical drive.
7) Search the forums for Vista support. As far as I'm aware, no. Vista is pointless int eh car at this stage of the game, IMHO.