Should I reseal sheetrock after removing wallpaper, before putting up new?
Answers:
I've heard you should always use primer and sizing. If the walls are already primed then just refreshing the sizing should do.
Just remember that you want the new paper you put up to come down just as easily when you redecorate in the future, so the extra steps today may really save you time and grief in the long run! (The contractor who built our home installed wallpaper right over unfinished sheetrock, so of course most of the sheetrock came down with the old paper. We had to have someone come in to replaster our walls, and it was such a costly nuisance.)
Good luck!
Other answers:
Depending on where you put the shetrock, is it in the bathroom? yes you should
Depending on where you put the shetrock, is it in the bathroom? yes you should
Yes, and the process is called sizing the walls.
It would be a good idea to prime the walls to ensure that in the future the wallpaper could be taken down w/out damaging the wall board.