Good luck. I've tried many times. By the time i get around to the rhythm section, I always end up having to rework the vox. However, this may be a result of my preference for really tough rhythm tracks.

I've done it a few times. Usually only when I get around to making the vocal fit and I find out that it can't. When I do live sound I always start with the vocals up and then add things around them. Usually because they're the thing in the room that needs the most help.

I used to do more actual work on the vocal early in the song, but now I am more likely to just rough it in, maybe pick the compression/eq but not any more than the rough settings. I do, however, just turn it down a few notches instead of muting it when I'm working on other things- if it's going in the background, I'm more likely to catch things that step on it earlier.