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.

Not from this photo cause there's no reason to assume it needs accenting -- is the kitchen in yet? If the toilet ever shows with door partly open, etc... I wouldn't do anything to highlight that area! Not saying the ceiling - but it can look good in a soft color, etc...

i agree with Ms. Rupal Shah as to get rid of the piece or redo it. If not you could probably use wallpaper to cover it. if not that even i have a suggestion for colour pallet. the wall opposite no. 3 should also be no. 3 and the wall opposite your green unit can have a custom wallpaper with shade 5, 4, and 2. you could also get a floral mural done in the same combination. Shade no. 1 (Sage) would be perfect for tufted head board for the bed. white bedsheets with large cushions in shade no. 5 (Burgundy) and shade no. 2 (rose pink) to top it off you could have some accessories such as: Dont forget to keep 1 or a few indoor plants too! Best of Luck, Purva Saksena (Architect)

do you have the interior designing and finishes finalized? as I mentioned earlier, everything in the room has to be tied together. I cannot give you a colour for the arch if it is going to clash with the window frame job, or the cabinets or the wood. In case you don't, I can help you with that. we offer consulting services, which is basically this, the help on Houzz, in a lot more detail. If you are interested, please connect with me on 9921364291 miloni The Yellow Cushion