Patching Cracked Drywall Drywall Contractors, Will You Answer Some Questions For Me Please?

Drywall contractors, will you answer some questions for me please? - patching cracked drywall

I intend to start work in a room. My house is almost 100 years and the walls and ceilings are plaster. The ceiling of this room has water damage and an interior wall. I pulled the wallpaper (which is also on the roofs), so I do not know how much damage it. However, there is a significant stain on the paper in these areas, so I know I must be bad. I is definitely with a maximum nine my question is, should I remove all the plates were made of plaster or new hire a contractor who would rather hang drywall on plaster? They study only cracks in plaster walls or drywall should be hung around? I have not started yet have a contract yet, but I could wallpaper stripes and overthrow the existing walls, if necessary. But if you go to the top is used in the drywall, then there is no right to anything? Thank you for your help!