I can only give a few answers, since I don't use Traktor that much:
1) You can set shortcuts in Preferences -> Keyboard tab
2) Unfortunately RB isn't as flexible as Traktor in that you can't have different layouts/user profiles and switch between them (extended, browser, etc. on Traktor) depending on hardware and use scenario.
3) Back up is done in File - > Library. I suggest you learn how that logic behaves, since it is different to anything else out there. Basically you have proprietary way in RB, meaning you have a separate database besides you music library. You can back up the database and music independently.
4) There sin't much in the way of customizing, only selecting bewteen number of decks and between vertical or horizontal waveforms. It's nect to the Prformance/Export select in the top left corner.
5) -?
6) Preferences -> Audio. Select Buffer size or click the Setting utility under Input channels.
7) -?