Most wallpaper is strippable however, some do come off in layers verses all in one piece. Fabric backed paper usually will come off in 1 solid sheet, depending on the prep that was used, with no to minimal damage to the wall. The key to making wallpaper both stick well and come off well is the prep of the wall itself. If you paint the wall with a thick based primer this will give the paper a smooth surface with a good grip, it will also protect the wall when you decide to remove it. Some wallpapers are rather thin and you can see the base color behind it, it can also have some shrinkage at the seam area. I prime walls to be papered by tinting the primer to the base color of the wallpaper. My paper hanger always uses wall paper paste suitable for the type of paper being used, even if the paper is "pre-pasted" for a better stick too. Yes, you can wallpaper ceilings if they are smooth. Back in the day they used to wallpaper everything, including doors.