I think an abstract landscape/water piece, with some color, would look fabulous there … and play into your wonderful views. It would also bring warmth in, while keeping with the very modern style of the room. I’d look on Etsy, on gallery sites, Ebay, and/or visit local places to find a piece that speaks to you. This is a prominent spot — I wouldn’t buy a big piece of generic wall filler. Art here could be the soul of the room. https://magazine.artland.com/top-10-landscape-artists-in-modern-and-contemporary-art/ I do like the idea of three b/w prints you posted — it brings to mind water movement.

I'd put blinds Bamboo blinds, more contemporary, on the windows and open the drapery panels on each side of the windows... only need the drapes pulled when you want a total darkness. I'd put large art in the indented area with a table and lamp Ambient lighting is a must for any room. A tall piece of furniture on that tiled floor that meets the carpet. I'd pull the sectional closer to the tiled edge... away from the window move the ottoman to the far side... and the side chair. ... find a new play room for the kitchen set.

The bed frame seems more Beaux Arts to me. Perhaps something like this in place of the travel poster. https://www.greatbigcanvas.com/view/lermitage,1993348/ And a set of small vintage frames on the window wall next to the bed.

I'm shocked by the first post. Not because I don't know the interet is like this but you have a lovely room already and its very inviting. Could you go for something like this in the dining room? I'd add a tall tree to one side -- or maybe frame it with two! As for the entry area, I'd rethink it to be more functional because most people really do need that space to put down stuff or keep stuff. That doesn't mean constant clutter. But it's okay if it's empty and maybe just has an attractive bowl or catchall or tray on one side. Actually Levenger's sells a note "bleacher" where you can leave notes, letters you shouldn't forget to mail or mix in a favorite photo or postcards. https://www.levenger.com/products/note-card-bleachers?variant=42555135787157 I would also want some kind of umbrella holder under the console. I'd put a walking stick in there too but I like to use them. But I wouldn't put flowers or books or candles. (I might go for a great flaslight!) https://www.ebay.com/itm/195840629086?chn=ps&mkevt=1&mkcid=28&srsltid=ASuE1wT9G_7DHE4jqL58TaDePa2o8aNCXVHxJfYglXtvAachZnUY5M80qI8