I would remove the cabinet and not put another in its place (maybe a tall plant instead); different artwork to coordinate with the dining space; and, agree that a bench would look great in front of the windows and it will be functional, too. A rug under the table (with coordinating runner in front of the bench) and roman blinds in the eating nook would tie the whole space together well...

IMO the first thing you need is aheadboard then the space left over is for your pictures. Maybe 3 framed hung at the same level as the octogon window above the headboard.

Love your cabinet! I agree that the area looks just fine bare. You have nice molding nearby, and not a huge empty space. If you decide it needs more, I’d do something like this. Simple and balanced (with the art going just above the height of the door). I like how this has a layered look: I do have art around my TV for something interesting to look at when the TV is off (it’s a big wall, would look awful empty).

That's immensely helpful. Your home has both angled and square corners for traffic flow. A bit of a challenge but not insurmountable. Cool couch set, wish I had room for something similar. I wouldn't worry about the "mess." Fairly typical of folks trying to figure out furniture arrangement. Be sure to take that into account though, the kinds of uses you will have for the space . . . and storage needs. I personally would want some type of bookshelves and/or storage cupboards in that cutout wall space next to the fireplace. I would for certain change the position of the beige armchairs, they look like what we call "time out" chairs for our kids, places you have to sit when you are not allowed to interact with the rest of the group. I can't see anyone willingly choosing to sit in them . . . . YMMV, I am an extrovert . . . Wallflower furniture . . . https://www.bhg.com/decorating/lessons/expert-advice/furniture-arranging-mistakes-and-how-to-fix-them/?slide=slide_b160fdf1-1919-43af-b007-659030b308c8#slide_b160fdf1-1919-43af-b007-659030b308c8 One of the slides here "Functionality First" reminded me of your space . . . https://www.hgtv.com/design/decorating/furniture-and-accessories/furniture-arrangement-basics-pictures Really great article focusing on living rooms . . .https://www.bhg.com/decorating/lessons/basics/how-to-arrange-furniture/?slide=slide_82935464-d7ef-4c4e-bb80-4a039a938f45#slide_82935464-d7ef-4c4e-bb80-4a039a938f45