A. Probably
B. I get all of my work done and then some, so I certainly hope not. The way I see it, neffing is just my version of a smoke break.
BUT, I don't neff unless ALL of my work is done or if I've been coding for 3 or 4 hours without a break. I usually only come here in between projects. When I project hits, I'll disappear for a few weeks.