Can't audio between markers; convert to range deletes labels; no way to snap ranges to marker

 You are trying to do this in Multitrack view, and that's why it won't work - this only works in Waveform view. Multitrack view doesn't deal with 'real' audio - a clip is only a representation of a file, showing just the bit you want to play, but it's not the file itself, and the markers only apply to the timeline - they don't move with the clips. If you want to split up a file like that, then you have to mark it up in Waveform view and operate on it there. This deals with the actual file, and is what is referred to as 'destructive' unlike Multitrack, which is non-destructive and can be altered after the event if you want.