I posted in March about my "nightmare wall" underneath wallpaper removal. I've done more work on it but am at a different crossroads, so wanted to start a new discussion.

Background: First thread (https://www.houzz.com/discussions/5645322/nightmare-underneath-wallpaper-what-exactly-are-these-layers) was about the daunting array of materials/surfaces underneath the backing paper and how to clean up the glue from them. Many useful insights from other Houzz'ers.

Now that I've "peeled back the layers," (w/lots of time, elbow grease, putty knife, DIF/TSP/water etc), I'm ready to patch/repair and prime the wall for repainting but unsure about *which products* to use at which point in time for which area, as I have various surfaces/materials that were underneath the wallpaper/glue, etc. The last thing I want is to prime/sand/paint etc, then have a mess when something cracks off/didn't adhere, because I should have known better about what goes on top of what.

The pictures show the walls after removing 1) the wallpaper 2) the backing paper, 3) the glue, and 4) skim coats and related repairs that were underneath the glue (in some limited areas like around the door frame, I left took off only the top of the skim coat). Essentially the nightmare seems to be caused by the wallpaperer not priming the areas with skim coat/joint compound (JC) nor the drywall. (h/t geoffrey_b !) This created a mess for me when taking off the backing paper and the thick, uneven glue; the softened skim coat got really messy underneath. I also wanted to remove the glue-infused JC layers, because I didn't want to take chances for my later paint/prime job. (You may opine that I made unnecessary work; I'll admit that I used to do archaeology so have a compulsion to know what is the situation underneath the surface!). I also enclose a picture of what materials I have gotten so far...so that you can weigh in.

So the basic questions I have now are:

1. *What material* to put on over **old,** not-all-that-hard joint compound that can provide a stable and smooth skim coat? (.....and which can then be coated with oil-based primer, etc?). If this old joint compound has absorbed some DIF into it (then dried), will that be problematic?

^--This question is top-of-mind because the wall around one door frame (see 2nd pic) is heavily skim coated with what I think is joint compound (I believe --see photo); it doesn't seem worth it to remove the skim coat/JC. Following on from that...

2. Where the old joint compound *only partly covers* a layer of oil-based paint (picture 2 especially) which still might have residual glue of some sort on the paint layer (despite much effort to remove!), how- and in what order -- should I prime this adjacent surface? Treat with same material (e.g. to skim over along with the old JC), or does it need oil based primer on that area s

pecifically? If it needs something specific, should it be applied before/after dealing with covering the old skim coat that overlaps it?

3. For torn bits on unprimed drywall (and areas where the glue can't be removed from it), is oil-based primer (Zinsser Cover Stain) ok to use for painting over these spot areas?

3. Around the edges of a drywall repair, I took the drywall tape off (overzealous! plus it was embedded in the glue-skim coat layer). I believe I should re-tape; would mesh or paper tape be better? and again, what material to use for the compound--and should it be before or in between oil-based primer coats (since I plan to prime surrounding areas).

4. There's also now-rough caulk around all the frames. What's the most painless way to deal with that? I thought of removing to re-caulk, but it doesn't come out of the crevice easily and doesn't sand.

Thanks for bearing with me all the way to the end!! I feel I'm come so far, but I'm at a standstill about starting the repair phase.