Nick66
Rock n' Roll Doggie ALL ACCESS
Making it louder = remastering.
You're fiddling with the master recording (i.e. making it louder), hence you're re-mastering it. Granted, it's not the preferred action to take (and jacking up the levels isn't a difficult thing to do), but technically you're still doing a remaster.
Not really. I mean, I supposed you could call it a "remaster", but it's not a true one unless you go back to the source tapes. You can pump of the volume, adjust the EQ and do any number of things to a recording without going back to the original master tapes. Hell, you can adjust the EQ and loudness of a track on iTunes or your home stereo.
So called "digital remastering" is done all the time w/out benefit of the master tapes. Whether its increasing the volume or just removing tape hiss.