I think there's room for a coffee table, so long as the console under the tv is narrow - only 10-12 inches deep. You'll need the coffee table for a place to set drinks, etc. Something on wheels would be good, or maybe something like one of these (above) I think there might be room for a small-scale occasional chair as well - placed where outside furniture is currently. It looks like there may be patio umbrella - which could either bounce light into the space, or shade the interior to some degree. For drapes, I would think sheer white hung wall to wall would do the job. What does look tight to is the counter stool(s). Could you post a photo of that area? It looks like you have quite high ceilings - it's a very nice space, although small!

Hi again, this picture shows the red T!!

Try putting TV on angle in the right corner. Then put sofa on angle facing TV. The bag seat can fit under window. I would also consider moving the white table on other wall (where ironing board is now.). You need a cozy rug and a nice tall plant. Maybe some art. Not much wall space so art will have to be scaled properly. Nice space, but tricky to use with limited wall space.

Have you thought about switching rooms? If dining table and piano were in LR, it looks like sofa and two chairs could possibly fit in dining room with room for armoire/tv where China cabinet is now.