I was thinking something along the lines of this... You can use the colors of the rug, like the terracotta, in your pillows on the chairs. It's too bad you don't have room for the alternative placement of the TV, and in that case I would get a console to put catty-corner on the walls next to the fireplace on the right, even though the windows will be behind the TV. Since you say this is not your permanent home perhaps that will do as a stopgap measure. The couch should be facing the fireplace, unless you want to angle everything to face the TV. The chairs will go perpendicular to the couch. The fireplace nook you can fill with a painting or perhaps an arrangement of blue and white Chinese porcelain (have a look at etsy). With a beautiful rug I'd suggest a glass and metal coffee table so the rug design shows through. You'd also need side tables but I see no way that you can have lamps without trailing cords. Find a way to display books on the tables, which give a lived-in look. Pardon me if I use pictures of my home to illustrate some of these points; your taste may be quite different, but it's just to give you some ideas. This rug is made of polypropylene and therefore much more affordable, but you can see how these colors would brighten your room and give you colors for pillows on your couch and chairs. You can find rugs on e-bay, overstock.com, pottery barn, just google area rugs and then indicate "traditional" or "oriental" and you'll find lots of ideas.

If that's a game table between the two chairs. I'm especially fond of that kind of set-up. Do you use the log box left of the firebox, or could you have it wired for the TV to go there on an articulating arm so it could be pulled out and adjusted for viewing? I know the FP heat might limit its life, but it would consolidate your two focal points. I find the sectional makes for a blockaded feeling - don't go near the fireplace, its dangerous. A 3-seat sofa and a pair of swivel chairs would open things up and make it more inviting to enter and be seated. Angle the sofa to face the TV, add coffee table 18" or less from it and the have the chairs face each other over the coffee table. They'll swivel to watch TV or to have conversation. In addition, if you entertain lots of people at one time. you could add a snack table behind the sofa with stools to match the ones at the bar. Seriously consider removing the drapes and swag valances which are really dated. On the sunny side, you might add some new hi-tech UV film to prevent fading of furniture and carpet. Probably a little too casual and man-cave like for your room, but the concept of the snack bar/sofa table is here if you need more seating on game day.

As for art, I do like the hexagons with plants if you can't find art that you love. I wouldn't make them just straight shelves. You need something with some pattern/color. MCM is all about clean lines like your sofa, but it was often complemented with large, bold geometric patterns. I feel like you need something to break up the large squares. Something with color or pattern.

Your best basic seating options are a 3-seat sofa and two upholstered armchairs. Placement options are pretty much unlimited. For more flexibility when TV watching is the main goal, the chairs should be swivels. You can place TV opposite the FP and float the seating. The window ends will give you space for some casegoods and some occasional chairs. And don't forget art over the mantel and on the four short pieces of the "north" and "south" walls.