The latest computers are 64 bit however you will not get the whole of the Final Cut Studio now. Only the Final Cut Pro x is 64bit GPU processing....and is not compatable with the older studio components/....quite a few FCP editors are nowe heading to use the Adobe software professionally.
Edit in cameras?/ Professionals set up bars and tone , time code and then leaves enough "handles" on he shots for when the material has been ingested into the editor before editing....in the camera..If you are not pro the FCPX will do you fine.....
Yes, I edit in the camera Let me show you how:
"Person walks on from stage left, Wide shot, Of stage + audience, Person is about to speak, Cut to camera 2 as a mid shot, bla bla person is talking away new presenter is about to walk on, cut to wide shot of stage from camera 4" ect.
Most of my editing happens as I am filming, Record a bit of spoken word than think "what next, insert graphic of importance here?" Or if I know they fumbled a bit in that spoken word bit I did but I cannot re-shoot "Get a cut-away of something interesting"
My brain is what handles the editing and the story telling, the camera is my import tool, the editing suite is not where most of the magic happens It's in the camera!