Recently I've been refinishing the walls in my bathroom - I peeled the
gloss-finish wallpaper off the greenboard, which was quite easy but
pulled the paper surface off the board in a few spots. I've been
skimming a thin coat of joint compound over the walls to even out
stuck-on adhesive, low spots, joints, etc., and where the paper was
pulled off the moisture from the compound seeps in and ripples the
paper surface under the new finish. I've been trying to prep these
ripped spots with paper drywall tape or drywall primer, without much
luck. Anyone know what I should be doing (or if what I'm doing I'm not
doing right)?

I've also noted the compound sets up very quickly on this job, probably
due to the thin application. I can get in maybe three swipes before it
gets unworkable. Any way to extend the work time?

VMacek