Just to make it clear, this is NOT our furniture. This was the previous owner's. Currently we have a large, straight run brown sectional couch w/ chaise and also a chair and a half. But picture the room as a wide open, empty space!

for the slider glass it depends on if these go with what you have or not as far as style and color. you may want to consider a type of faux wood or bamboo shade for privacy. the corner fireplace is great, I don't see anything weird about it. The way this room is arranged though is very lopsided making it too heavy with all the furniture pushed on one side. Think about wall mounting the tv over the fireplace. What are your current furniture and decor color? Hard to say a wall shade without knowing that.

I guess the fireplace looks awkward to me when thinking about incorporating an entertainment unit or something for a TV. That's why we need help though. We own this couch, but want a young, bright (as possible with this couch) tropical feel. If I could do anything with the room, I'd want to channel Lily Pulitzer, which will be hard with a big, brown couch.
I also want to maximize and reflect light, as the sliders are the only natural light (townhouse).

mirrors always reflect light. use bright light pillows and accents to brighten things up. stay neutral tones on the walls and all color with accents and decor. (neutral doesn't mean beige anymore either.)

I would remove the window treatment--they look heavy and dark. Shades in Place photo pics are definitely what I would suggest also.