Pink and gray are beautiful together, though honestly I'd prefer the gray on the walls and the bright pink on the curtains and accents. A little pink goes quite a long way. But if you are committed to the pink walls, then I think a gray and white patterned fabric for curtains would be lovely.

Rowe Furniture has very clean line sofas that I think would be an appropriate scale for this room. LOVE the red feature wall. You do need to bring the red into the room but knowing how you want the room to feel can help determine a color palette. If you want the room to have energy and "pop", try a split-complementary or triadic color scheme. If you want it to be more relaxed and harmonious, I would suggest an analogous color scheme.

On your paint problem I can't be much help. This usually happens because of damp -- please get a damp expert to make sure that there isn't any damp lurking in your walls. I had this once when I had pipes leaking inside the walls. I didn't know that. The other alternative is something like painting before the plaster is dry or some kind of chemical mismatch. I do know you will have to scrape all the mucky powdery stuff away and start again, at least on those areas. Don't try to seal and prime and repaint until you know exactly what the problem is and how to fix it.

Looks like some of them open...it would be cool to get some glass paint and paint the windows to look like stained glass...just pick you favorite colors and go at it