A rug has to be 36-42" larger than your table top, yet not run into walls or furniture on the walls, so you don't have room. First, I would make sure that the table is centered with the windows and under the middle light fixture so you can replace that light with a chandelier to hang 30-35" above the table. I would hang the art on the blank wall, centered 5' above the floor. It is too wide to hang above the buffet/wine bar. You may have to move the buffet some once the table is in its rightful place as the center piece of the breakfast area. You can put the sconce shelves above the bar, but one higher than the other and about one hand's breadth apart.

My problem is that if I move the bar to the middle, the dining table will not be centered and closer to the opposing blank wall creating an unbalance. So that may not work. I was trying to incorporate the furniture from my old house.Into this newly constructed home. I may have to look for new ideas (pieces).

I would not add a rug. The bar is too large of a scale for the space. It is lovely and hopefully you can find a new place in the house elsewhere. Center the table and chairs with the window and see if you can find a piece to work at the end. Best wishes!

I'm not suggesting the bar be moved toward the window, but perhaps further from it to allow for centering of the focal point, which should be the table.

I would rid of sconces in dining room and get a rug, wall art on empty wall and clean up the top of kitchen cabinets too.

Do you mean no decoration on cabinets?