Brian - thank you for additional insights.  Given this is in the center of our house I want to avoid oil-based given the smell so I like the water-based option you recommended.  I think trying water/soap would be good to get the surface better prepped.  I've also heard of using water and fabric softener to remove wallpaper so wonder if that would work here (would smell nice anyway)??  I did some drywall mudding in a prior bathroom remodel but if we can remove and then Kilz, I think that would leave a better surface given my (limited) skill level (there'd just so much one can learn from YouTube, although it did allow me to fix issues where a wall had ripped drywall paper and other problems!).