It's refreshing to see nautical, navy BLUE. Everyone is saying the same thing for the most part - just introduce another color, definitely bright (yellow or orange IMO) and it will make it more current. What I really like is how your style will withstand the test of time - and with minor updates now and then it will always look fresh and "current".

I would use a bookcase unit with closed doors on the lower half and not too high. Wide and low maybe. Closed lower cabinets are great for toys, games and will not clutter. Open shelves tend to get cluttered after a while. When displaying books, use in stacks standing and lying down. Open space between groupings, not all lined up in rows. Add some decor items sprinkled among the books to give the eye a visual break. I would choose a horizontal art piece for the chair wall. Add some art on the long TV wall leaving a lot of bare wall between the TV . and the artwork between the corners of the chair wall and the window wall.

Ozbern: we had a similar dilemma, lovely backyard and then they started tearing down bungalows and building four story townhouses all around us. I built a single depth pergola along the back property line, the beauty of this is not only the privacy, but it brings the scale of the yard down to make it feel more intimate when we are outside. We also added a 10' x 10' (little over three meters) pergola right up against the house where we had a wall of windows. Will try to find that photo too. We have coral vine now growing in it. Dies in winter, comes back in spring. You can always do more contemporary details if this is too casual.

Mod Podge is the best stuff for decoupaging. That is pretty much what you will be doing except with a much larger piece of paper. If you do this procedure make sure you coat the completed item as well, not just what you would do to make it bond onto the wood or canvas or whatever material you are using. Have fun!