One of my favorites...BM Mineral Ice

I would use the same paint color you use in the living room to provide continuity. The spaces are too open to each other to change color. Given the Eames chairs you have chosen, (those are GREAT) I would use some really tailored drapery panels over the shutters in a mid-century modern print for fun as well as to bring in some color and personality! Your lighting is so fun it should be reflected on the fabric you choose.

Plain and simple stainless steel sheets available at Lowes and Home Depot. They come in square and rectangle . Easy clean up , looks modern, stone is nice but keeping it clean will be difficult. Unless you never have pasta sauce, bacon or gravy splashes to worry about. The Stainless backdrop will really make your cabinet stand out.

I don’t know why the builder doesn’t just continue the wall to ceiling but they do the bumpout to make an entrance to the bedroom. I wouldn’t love the ledge but you might Just get it sheetrocked all the way up if it bothers you a lot. Google tv stand or tv credenza look at other options. One that is bigger or warm wood might please you more. You also need different decor to visually “connect” the television up on the wall to the credenza. Take a look at this pic to see what I mean...