This is a dilemma indeed! Posts in the middle of rooms are always a little difficult. It would be helpful to have pictures of all four walls to suggest the best layout. From what I can understand of your dilemma, I've attached a layout that may work based on your description. It features a defined entry. So when you walk through the front door, you will see a console table with a couple of ottomans stashed beneath. They can come in handy for extra seating. In front of the console are two arm chairs, followed by a modular sectional - they make up your main seating area. To the right of the kitchen door is a TV console. Behind the sofa is a bookcase and to the right is a round table with a couple of chairs for games, paper work or what have you. You don't mention any windows. Is this the case? If so, we'll want to make sure you've got adequate lighting and colors that will work with the limited light. Hope this helps!

Do you live in a warm country - then you might want cool colours: pale blues, greys or greens. I would leave your bathroom as it is - love the niches. To add some cosiness to the marble floors, find a nice cream carpet and cream furniture and then use this as your base for colours that you like. BTW what colours do you like? What inspires you. When you travel or go out ... what is that makes you happy? This will help

I think a comfortable distance between the island and the counter is around 42". It seems that you have only 30" between your cook top and the counter. I might be a little too tight. The wall between the entrance and the kitchen could be 4' long instead of 6', you would then be able to move the island a foot which would give you more room between the cook top and the island. Could you switch the location of the toilet and vanity in your dad's bathroom so your enter facing a vanity instead of a toilet which is a lot nicer.

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.