A photo facing the fireplace (standing as far back from the fireplace as your can), a photo sitting on the couch, and a photo standing with your back against the fireplace would be very helpful.

Don't have time to answer all of your questions but here's what I can suggest: 1) Lower the mantle on fireplace a little, as well as the painting in the niche. (See #2 here) Consider changing the mantle to something less rustic and paint in color A (see next suggestion) 2) Open spaces should be cohesive - which you can easily do with paint. Choose 2 colors or 2 shades of the same color and vary placement in different areas. (see #5 here) Consider adding a simple chair rail to the dining area. For example, with minimal effort, you could use color A below the chair rail in dining area, as the dominant color in window treatments fabric (I"d use draw drapes) , the back wall of niche, throw pillows, lamps ac, and maybe an area rug in living room, and in accessories (see #3 here) in living room and kitchen. I'd consider adding some of that color to kitchen also -- back of open cabinets for example, recovering bar stools and dining room chair seats to match drapery fabric and possibly slip covering one of the armchairs in the living room in a pattern that incorporates the wall colors with other colors in the space. You want to use coordinates, not just the same solid everywhere so look for different textures or patterns to add. Hope that helps. I've inclluded links to additional info about topics I mentioned that I think you'll find helpful. 3) see #2 - I'd choose lamps with either a base or shade to match color A. (See #7 here) 4) Add plants. If you aren't there often enough to take care of them, use artificial greenery.

I really Ike the colors and patterns that you have in the space. It is not so easy to combine patterns the way you have done. You seem to have a natural flair for this. I had also thought of a solid ottoman in an orange, as being an interesting possibility. i like the overstock piece, also. I was thinking, with your white sofa + red pieces, a color like this might also work. https://www.overstock.com/Home-Garden/Handy-Living-Duncan-Parisian-Tan-Gray-Velvet-Large-Tufted-Cube-Ottoman/8119649/product.html this one is out of stock right now, but just to show the idea/option. Although I might lean towards an untufted piece, since all of your furniture has some tufting detail.

I'm a fan of #2. I always like the look of two club chairs side by side like that. I think having them together as one unit balances out the heft of a sofa and the huge TV. I agree that it makes sense to focus on the coffee table first. Are there any textures in your room? If everything is just flat wood, paint, and upholstery, I'd suggest a coffeetable that has a bit or texture or reflectivity to it. What kind of books are you looking to store in this room? I got a three tired brass and glass coffee table from West Elm recently and it is a fantastic place to display 12 huge art books. Better than a bookshelf. When people sit on the sofa, they actually gaze that the books, pull them out and read them. I like that.