Swapping the rooms is always an option and could change the usage. Perhaps a more simple update would help, like adding some area rugs and changing the pillows. But, from what I see, the 'curtains' seem to dim the natural light in the room, leaving it feeling drab. Try changing them to simple panels from perhaps Bed Bath & Beyond. Place panels on the outer edge of the bay window and the edges of the dining room window. Painting the ceiling a lighter color might help the room feel more welcoming.

the ones in the living room, they are lovely. its ok to have some darker finishes, i think the shades are handsome. a light colored rug would work miracles, too... maybe do that before painting the ceiling.

and larger art rather than your 4 taller paintings would be something to aim for down the road. this kind of transition can be done in baby steps. change one thing, take a picture, see how it compares.

plan it out everywhere before you begin.... work out the difficult spots rather than having uh ohs when all the easy places are finished.

leave your lamps alone, they get to stay rich looking like your chairs. choose panels and rug that are ivory, bisque, parchment.... whatever color it is in your chairs. hard to tell from the computer screen.

you can even keep your darker pillows on the couch, just add another thats light and dark pattern with mostly light.

I do love those paisley chairs!! I would start with a light colored rug in each area. Add some lighter colored pillows. Solid panel curtains on the outside of your rods, the sheers in the middle.

I would wait to add the wainscot detail until you get some other things going in the direction you want. Then if you think it needs it. However, I'm not a fan of the bi-color. If you do the trim detail, paint all one color. Otherwise you have too many things going on. :)

I think your room looks good the way it is (with the curtains open for more light). It just looks a bit unfinished. Another couple of pillows on the couch would be good, but, the biggest thing would be to add a nice area rug to both the living room and dining room. It will make a huge difference. Make sure you dont buy too small a rug, since a larger one will look much nicer.

Second what cat_ky said!! :)

And yes, I think I'd go solid curtain panels in each room. Keep your sheers, but just add another layer.

For an instant lightener, paint under the chair rails in both rooms the same white you already have on trim and ceiling. Paint out the dark burgundy with more of the light yellow. Then change the interior part of your LR ceiling to a pale pale blue version of the blue/green in your paisley chair fabric. All the curtains need to go. Replace them with fiber shades and flank each window area with drapery panels that do not close, hung floor to ceiling. I think all three lamps are too petite and too Hobby Lobby. Start shopping for new ones, along with a new sofa more in line with the sleek style of your two slipper chairs. Keep your eye open for a stylish fabric to reupholster the dining chairs.