i would ditch the valences, or replace them.
painting, i would do the beam in the ceiling color. no need to accentuate that you lose headroom.

rearranging the furniture to make the room seem larger would be a good idea as well.

It's a nice room and what you have to work with is good. There are a few good options for you to choose from. I would check your local Home Depot or Lowes for "Oops" paint. It's a lot cheaper and usually readily available. I would stay with neutrals and keep the ceiling white. Is the red runner rug covering any stains? If not, you might put it under the table. I would take out the chair or put it in the corner behind the sofa with a simple bookshelf against the back wall where the mattress is now. Perhaps a reading lamp between the chair and the bookshelf. You could also use the rug running parallel with the back of the sofa for the reading area. I would take down the valances and leave the shades open for extra light. No matter what decorative window covering you choose, the new owners will probably change it anyway. It looks like your artwork is nature photos, which is good. I would continue that theme on the other walls, as nature is neutral and won't turn anyone off. Remember, less is more, both for your pocketbook and appealing to the masses.

i would take out chair and the runner. Then i would rearrange the sofas and coffee table closer to the tv to open it up. I also think bamboo blinds would look nice. I bought mine at home depot right off the shelf. The paint looks fine from pics.

The room really needs color. I would take down the valances and photo frames. Remove the lounge chair and rug so as to make the space feel larger. Add a soft color like Sleepy Blue by Sherwin Williams. I do agree with the bamboo blinds if you want to spend the money.