Greys would look good in these rooms. I wouldn't paint the paneling. Rather than a mirror over the fireplace a large scale painting would look good.

Shutters sound like they would be a great addition to your new almost at the beach house. Is it an open concept? If so while you can change things up a bit you'll want to repeat some element and ensure that everything looks great together. Even the rooms you're thinking of putting drapes in might benefit from shutters or wood blinds for both looks and light/privacy control. Also be aware of how these windows will look from the outside. When choosing fabrics look at your existing furniture for inspiration or a piece of existing art or if buying new furniture think about the windows as you do. Everything in the room ties into each other. Ideally you would have swatches and samples of every finish in the room from flooring to window coverings and everything in between including wall colour, area rugs, bedding ect to help make your final decisions easier.

Oh, and a few months ago, I was playing around. This is what came as the result :D

Thanks for the replies! My wife suggested we talk to a local real estate agent, so i think that is a good idea... just that Im not sure how helpful they are likely to be if we arent selling yet :) As for saving for our dream house, I dont disagree, however if doing this up nicely over the next ~5 years or so while we live here nets us some extra in the eventual sale, then that of course will help us as well. Interesting thing happened today actually. I got a knock on the door and one of the older neighbours asked if he could take some lemons from the tree. I of course said yes. Anyway he was telling me he had lived in the street for 40 years. I asked him if the house had always looked like this, and he said no that ~30 years ago the old old owner did a massive renovation and pulled off the timber and put up the bricks and gutted the inside of the house. Interesting stuff!