The first thing that bothered me in this room is the distance between the seating area and the tv area and that both seem unrelated in everything. I think what you should do to pull everything together is the following: 1) Move that sectional away from the back wall and the curtains (placing couches against the wall is outdated now) and closer to the tv 2) Center the coffee table under the chandelier with the sectional placed 16 inches away from it 3) get a console table of a height equal to the sectional's back 4) place few decorative items, stacks of books, candles, lamp shades whatever you find suitable on the console 5) someone mentioned that the two accent chairs are not in scale with the room. I totally agree with that. You need wider chairs with a low back 6) A rug is a must and two are better than one, layered of course !! But make sure the biggest one is big enough to place all the seating on it. 7) pillows and a throw will add warmth and texture too...

How do you decorate your place, what kind of style, colors, and feelings? That will greatly influence the type of door you might want. Also, think of your budget, and whether you want to install it yourself or hire a professional (you don't need to tell us, just keep that in mind). Then look around Houzz, in the products page, they have lots of interior sliding doors and hinged ones, from elegant frosted glass in a dark wood frame, to rustic reclaimed wood planks. You may not want to purchase that exact model, but it might give you a better idea of what would fulfill your airflow needs without sacrificing style.

I'm not against colorful homes. There's bright, and then there's too bright. I wouldn't go with persimmon for the whole house. The photo you provided has lots of white trim which offsets the orange, but your house doesn't have that much trim (unless you were planning on adding some, which I think would look good no matter what color you ultimately choose, but even so, I wouldn't go with persimmon for the whole house, as it's still too bright). To repeat what @nwduck said, the other homes in the neighborhood don't appear to all be done in the bright colors, and so yours would stand out too too much. I like @deco's idea of the bright door, if you really love a bright color. For the rest of the house, any more subdued color would be fine, along with additional trim around the windows, and assuming that your siding color coordinates with your roofing color.

Are they real wood doors? Can't you take them down, sand them, and restain them? Or pay someone else to do it if you can't?