Putty or painter's fleece?
I think you can't equate them. You putty to achieve a smooth surface. Painter's fleece can only do this to a limited extent because it, in turn, requires as smooth a substrate as possible. However, the fleece conceals the inevitable cracks and serves as a base for the paint.
When I read that you want to plaster Q3 in the storage room, I would advise you to change the "or" to an "and" in the other rooms ;-)