Not that I have that much experience, but I cut and paste a lot to build up my scratch tracks, mainly cause I hate playing to a click, then play the parts all the way through, usually twice or three times unless I nail it on the first go (like that ever happens), then I listen through to make sure I feel like I can mix and match to put together a good track and move on, or maybe re-record a section here or there if necessary. Later on, when I mixing, if I find a spot where I can't get there by combining takes, and doesn't sound obvious, I'm happy to cut and paste between verses or between choruses. As somebody else said, though, it's always track by track. I've never copied whole sections.
J