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.

also have uploaded a photo of our piano and mirror which I love. and I photo of our dining room light which I would also like to keep there.

My ex-husband and I had an issue with a large window that looked out over a sidewalk where people were constantly walking by and looking directly into our living room. We solved the problem by using window film that was one-way so we could see out but it was like a mirror if anyone tried to look in. There are other varieties as well. We still got all the sunshine and light but didn't need to worry about whether or not the neighbors could see me watching tv in my nightie on a sick day...It also meant the door to door salesmen couldn't look in and see that I was home when I didn't answer the door. http://www.gilafilms.com/en/privacy-window-film.aspx#.VOuUBS5vksQ

You are correct the place does and always will look a bit sparse when you only have blinds. The question with curtains is sometimes dependant on what climate you live in and I am not sure where you are so I am going to say. If you need curtains for heat go for a quality curtain to the floor with a fabric that is not stiff (as I discovered I now own after buying curtains off line for my spare rooms). The expensive curtains I brought for my living room have a softer texture and hang so much nicer. As I need Curtains / Roman blinds for heat I have backing fabric etc on the expensive made to measure ones, where as the cheaper ones are just thermals. If you only want to add a curtain for looks and do not require it for heat I would recommend going with a lovely sheer / half see through fabric that drapes really well, this will add a point of interest and you can colour match or add a loved colour to a bare - white on white - cream on cream - colour scheme.