The problem I see with a lot of the stuff you are doing is that if the
prospective buyer doesn't like yout tastes, they aren't going to pay
extra for new stuff that they don't like. However, I'd probably prime
the attic and clean the kitchen cabinets real good. #2 is hard to say
without a pic. And painting over wallpaper is a poor practice, but
common. Actualy wallpaper in a bathroom period is a poor practive. It
will peel eventually.