The first thing I notice is you bought a too small area rug, although I love it. Many people make this mistake because when you jump to an 8 x 10 or larger, the price difference is $500 and more. I would definitely put it under the dining table and find a larger, perhaps jute rug which aren't as pricey as wool/fabric. Check homedecorators.com for rugs. I love the art for the dining room and would use that as your inspriation for other colors to add. I like your color choice in drapes but the pictures aren't the greatest so kinda hard to see this room and colors.

I like your idea of a round coffee table. Since you're a fan of contradictory styles, like chic and rustic, I'm not convinced it matters what kind of wood the table is. I agree that green would be a good choice for your new drapes, perhaps even in a small patterned fabric. If it's possible, you might want to try exposing more of that rug, as this space could use a much larger rug than this. Yes, it would be good to resist the urge to hang that picture too high.

Since the kitchen table is staying, you need to match your coffee table to it. Find an oval one in oak! Do try this rug under the table, hang the drapes at both the window & slider??? - high like you said. I think it will look very different.Keep your eye open for a huge woven fiber rug - maybe bound with brown - to put under the sofa - extending out at least one foot in back and wide enough for end tables to sit on it too if you want them. You might consider window treatments in the same green as the picture frame and/or the sage in the floral rug. Resist the urge to hang the picture higher than the door/window frame or lamp shade, even though you have a vault at that end of the room. I think you're getting somewhere!