This is all a part of what I would refer to as lining it up. What ever you gotta do you do to make it sound right.
Chop, stretch, pull, rearrange, what ever. And that's the part about it I like the most. Then comes the mixing part and that's what I really don't like.
It's like now the fun part is over and now the work/grind part starts.
I dunno often messing with the vocal like that can sound a bit unnatural, would also take really long and tedious to do.
Mixing the vocal is easy. Just sit it *just* above everything else.