I understand about sticking with budgets. What kind of exhaust fan do you have? If you put one over the shower area and add an automatic humidity timer, that may help with ventilation problems. I'd go for the post at the corner to add stability to the whole thing, especially if the exhaust fan option is to go directly through the wall instead of up through the ceiling and out to the wall. With a washer and dryer in the room, ventilation is important.

I agree with Hallet that if you are able to post a photo, you will get much better and more specific advice for your room. But in general, covering the entire wall with curtains could be a missed opportunity to bring in some art or a mirror, depending on what furniture is in front of that wall and location of window.

a black wall doesn't relate to anything in the room. so no. what I would do is wall mount the tv (not too high above the console. maybe 6-8" max) . Also make sure that console is going to be long enough. TV should be 2/3rds the size of the console or else is look out of proportion this is a good visual this one is borderline, but they put the soundbar beneath it and they have taller objects on the console so that the height doesn't look off. wall art around the tv give it some balance. Not my decor idea, but it works. You could try something like this: or like this

You don't have to fill every wall. Might be a good time to slowly start collecting art pieces that you love ... buy them at art shows, antique stores, when traveling, etc. You can then do a gallery wall with the pieces you have collected. And it doesn't just have to be art. I found this large 13" Moroccan brass door knocker at a store in LA and hung it as part of my large gallery wall.