I think that the clock over the fireplace is killing your mid-century vibe, look at replacing it with some kind of art. LOVE the entertainment console, that is great! Have you thought about turning the sofa to face the fireplace and adding a couple of small mid-century accent chairs? I think adding a mid-century coffee table would also help For drapes I would do a simple white sheers from floor to ceiling. For the pop of color aqua and orange were very popular for that era. Add the pops in your art and throw pillows and accent chairs if you want.

You might consider the new Samsung Frame Series. Tv looks like a piece of art, when not in use. Select from preloaded art or choose your own. Change when you want. I notice you have large speakers. Can I ask how new/old they are? https://www.bestbuy.com/site/samsung-65-class-led-the-frame-series-2160p-smart-4k-uhd-tv-with-hdr/6264695.p?skuId=6264695&ref=212&loc=1&ref=212&loc=1&ds_rl=1260573&ds_rl=1266837&ds_rl=1266837&gclid=Cj0KCQjwrpLoBRD_ARIsAJd0BIVVEGpbrXbYL4sus5k7QiakcLLfni2RlKk4VXX_QdHkW9_hXBT99pYaAkwxEALw_wcB&gclsrc=aw.ds

I put LVT in my finished basement a year ago and am so happy I did. Carpet shows traffic patterns and doesn't last as long. I got an inexpensive area rug (pattern was being discontinued) to define the TV/family room area. I also painted the walls a white with a yellow undertone to brighten it up. The only thing with LVT is that the installers need to check to make sure the floor is relatively flat before installing. If it isn't, they have a way to fill in the low spots. While you won't be able to get it completely flat, just make sure you don't have any low spots in noticeable areas like at the bottom of your stairs. Most basement floors aren't flat (you can't tell with carpeting), so make sure they check. The floor doesn't have to be the same color as the upstairs, but this also depends on how the stairs are covered. Mine are carpeted so you can't tell the floors aren't identical. If you put new carpeting on your stairs, tell the carpet store you are doing stairs so they can recommend a product that will hold up well for that use.

Depends on your budget- if no big changes can happen now, move your TV cabinet to the wall where the tall cubby is and use it as an entry bench- get a cushion made for it. The TV sits too low. You could turn the large cubby on its side and use it as your TV stand- but don’t fill with random stuff- use books, quality. You could also move the large cubby to that little enclosed area, add wall hooks, and your kids’ things go there - cubby could be painted to match walls to appear more custom. A large area rug with a streamlined couch and a chair or two that are not bulky- check consignment stores and FB marketplace- there are some nice quality items you can score. You have to be willing to put in the time and effort.