Yes, always record at 24 bit. It means that you can have the levels set safely lower than the peaks and not incur a noise penalty. I try to keep my peaks in live recording at -8dbfs to -6dbfs, just in case anything comes along and surprises me. And, with modern digital recording, at 24 bit you can have a signal that's quite low (-20dbfs) and still pull it up to full level without too much added noise.
As far as the editing, you might want to leave out the fade if you are assembling an album because that might be something that you might want to change in the context of the other music around it. Also, it can add noise when other processing is done, even if it's minimal. Definitely edit out any noise you might have, but if it's just a live to stereo track, find out what kind of noise reduction the mastering studio might have. It can make a difference in quality and would be better than the stuff that comes with editing software. Some noise reduction software, like Sonic Solutions, CEDAR, and to a slightly lesser extent products like Izotope RX (which I use), can do amazing things and not harm the fidelity or dynamics of the music.