priming old bathroom
In the bathroom of the house I bought recently, I pulled up the 40 year old wallpaper and found that it was applied directly to the drywall. The walls have a yellow look about them with some white smears. I am assuming this is the residue on the drywall. There are mildly rough areas where the paste is, but I fear washing the paste off and damaging the drywall.
Is it safe to simply seal over the paste residue using GARDZ and paint from there? Should I sand down the slight texture of the paste residue and then seal with GARDZ? Is GARDZ the best choice for a humid area such as a bathroom?
Also, in one small spot, when I pulled up the paper, the top layer of the drywall came up. Should I sand/seal/skim that area and then paint, or is there a better way to handle it?
Thank you so much for all of your help!