I tore wallpaper off in the master bathroom and fixed any holes/tears in the walls. I just put the first coat of Kilz2 on to prep the walls for painting and some of the drywall paper is bubbled! Am I rolling it on too thick? I tried thinner coats but it still seems to bubble in spots. How do I fix this and where do I go from here?? Ugh!!

The 16x12 plaster ceiling of my 80-year-old basement has some texture that I want to be rid of. I am not sure when the ceiling was last painted, of which type of paint was used (doesn't seem to be flat latex ceiling paint). There are some bubbles in the paint film, but this problem is limited to a couple of areas. There is a small crack in a corner (exposed lath), which will be repaired. I asked a general contractor (who is not a professional painter but who does painting as part of his business) who is doing a bunch of things to skim coat and paint the ceiling. To my surprise, he said he doesn't recommend skim coating. Instead he recommends putting drywall on top (bottom?) of the plaster to have a smooth base. He says that the skim coat will fall off. This doesn't make sense to me. I thought scrapping the bubbles, spot priming (or perhaps complete priming) with zinsser 123, then skim coat with easy sand setting type lightweight join compound, then prime and paint would be fine. Is this a good strategy? Is there any reason why a ceiling like the one I described could not receive skim coating? Thanks