(1) Is there a way to eliminate empty time? in other words, you can delete what you've recorded, but the time remains. You can slide what comes afterward to the "left" to eliminate the empty time, but when you have a lot of segments that's unwieldy and I often make a mistake and wind up overlapping the segments
(2) Is there a way, then, to merge the segments? I'm not talking about merging tracks. I'm talking about stringing "horizontal" segments together so that they become one (i.e., the opposite of splitting a segment)
(3) Is there a way to transpose a loop so that it's not in the key of the rest of the song? (I'm guessing no, because I tried to do this by making a new song in a different key from my original song, recording a piece of loop in that key, and then copying it and pasting it into the original song -- the result was, it transposed it into the key of the original song). I guess the only way to insert a piece of loop in a different key is to record it, save it as an mp3 or something, and then import it into the GarageBand song. Very unwieldly method, however)
(4) When I put a loop into a song, I slide it onto a track and I find it goes on and on. This is not horrible -- I can just split it and delete what I don't want of it, but I'm just wondering if I'm putting the loops onto the tracks correctly. It seems sort of messy, the way I'm doing it, but there's no cut-and-paste option for this.