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.

DEAR SIR, CAN YOU TELL ME WHAT IS COMMING A ELECATION COLOUR

you can give some live colour to walls, can put beautiful wall paintings and some indoor plants give peace to house , beautiful designer lights , textured paint .... all of these will help to give attractive look to your corridor.

I know all the houses in side would be beautiful, but went with the last one as the tiles outside give me enough info to have an idea of how beautiful ( if not beautiful) at least layout wise and material wise, how it would be, Now, can we see the inside please? hehe*