1) No, not at all, but it will make this easier (maybe too easy for some)
2) a) I don't know the exact number, but I think it is between 0.5% and 1%.
B ) Unless they are programed to, no
C) Yes, they are a folder in the downloads (graphics--->battlers)
3) Under normal circumstances no. You can go to the 'Request a mon' thread for a custom starter (or ask someone to trade you mon in place of your starter, I suppose)
4) Depends on your strategy and the mons you chose.
5) That quest start is the same and is still ongoing into the next episode.
6) Very open ended, but: Krickatune is a good crutch pokem for the first two gyms; always have common candies on hand