Pardon my ignorance...

I've got a new frame arriving in the next day or so...will slooowly build it up with new parts, but in the meantime I (well, technically going to have a LBS do it) plan on transfering everything...stem, handlebar, gruppo, saddle, wheels.

Couple questions:
1) the bottom bracket should be able to be used, right?

2) Does the spacing of the dropouts dictate whether or not you can run a 9sp or 10sp cassette? My current rear wheel is a 9spd, and when I get around to getting a new wheelset, will plan on a 10spd...curious if both wheels will work