I need to do the proper prep for old cracked and peeling plaster walls in a 1920s bathroom. The walls and ceiling have substantial cracks as well as very thick peeling paint that almost seems like very thin plaster. The last time this small bathroom was painted, a supposed “professional“ did very little prep so it unacceptable and I would like to do the most professional job I can. I also will need to use kilz since there are small spots of mold in a few places. I’m hoping to get a fan installed too in order to solve the moisture problem.