There are a few recessed lights and one floor lamp, but all are along one wall. The furniture is dark and the draperies darken the room even on a bright day. Rather than the purple drapes, why not consider light-filtering grasscloth (or similar material) which allows light to come through and allows you to see outside even with the shades down. After dark, you need another lamp or two to illuminate the room...a table lamp or two, another floor lamp. Light-colored art and a piece or two of lighter-colored furniture may help balance the dark tones.

Yes, yes, yes to all of the above.

I think the space would appear more spacious without the area rug.

That arc lamp is kind of wonky, can you adjust it so it's level?

I think you could find some pillows on Etsy that would add some interest and texture to the space.

I agree that you need some lighter colored drapes. Your room is too dark and the light is not balanced. You need to spread your lamps out around the room.

It's spaces like this that are hard because I do really love everything you have going on so far, if anything maybe just some more fun pillows and a little less stuff on the entertainment center, and find another place to stash the folding tables.