We are renovating our 70's cedar clad pole house. My husband painted between the ceiling beams in the kitchen/dining/living open space. He has just finished laying parquetry on the floor. We felt it was in keeping with the wood but felt the ceiling needed lightening up. It definitely brightened the place. I love it. I also sprayed some light fittings that were green fake verdigris with white paint. That also updated without detracting from the retro feel. Our kitchen has cupboards painted white and some drawer fronts in a wood finish.

Sounds like you've made a decision not to cover any of the brick. Just to answer your question - the masonry adhesive is applied to the brick surface (not the Gyprock) in blobs approx 450mm apart. It sets pretty hard so to remove it at a later time you'd probably have to chisel it off. Any residue left in the surface of the brick could be touched up with brick coloured paint. Apparently you can also use cornice adhesive. Same way of removing & hydrochloric acid would remove any residue.

Too much of a feature becomes a distraction. 70's / 80's brick interior houses were great then but are clearly dated now. One feature wall with the other walls in smooth plaster can still work, provided you address the feature wall as such, by not cluttering it with stuff. Try keeping the furnishing minimal and selected feature wall type dressing. hopefully this way you feature wall will look stylish. Hope this helps. Alfred Botha. www.gapdesign.com.au

I agree with both your painter and your Google result. The issue is something that has soaked into the surface of the old wall, particularly as you had an odd result when cleaning. You can’t expect the painter to sand and paint as part of the original job but they may be able to offer advice and action if you’re prepared to pay them. If you want to DIY I’d be sanding the wall and trying some stain locker undercoat.