I am currently repairing a small section of wallpaper in a room which has scrim walls. I have replaced the scrim. Can I use ordinary wallpaper glue to stick the paper to the scrim or is there some sort of backing I should put on first?

I have painted a room below chair rail height using a level line. I then stenciled a prepasted wall border to go above it. My problem is this - I created a level line 6 inches above the paint line - however when I measured it the line goes down - a lot ( around 2 inches from one side of the room to the other) Am I doing something wrong? Should I use this level line and not worry about the actual distance from the floor or should I make it equal distance from the floor and not worry about level? This is my first wallpapering type experience and I don't want it to be too messed up! I appreciate any help!