There are some "rules" that you might find helpful in tying your rooms together. 5-5-75 is one that usually works well when hanging art/mirrors. Hang centered 5' above the floor or 5" above a piece of furniture. The art/mirror should be no wider than 75% of the furniture's width. Your mirror is too large and heavy looking to hang above that buffet, even with the leaves up. The art above chests and lamps in the living area is too wide for those chests, which look very bedroomy to me. Perhaps you're just making do with them for now. Rugs would help a lot. Rug under the table should be 36-42" bigger than the table top all around so you have room for chairs scoot/sit space. But it shouldn't run into the buffet. Under the leggy sectional, I like the sofa to sit entirely on the rug with at least a foot or more extending past the ends of the sofa. Your sofa and dining light are very modern, but the other items aren't. What look are you going for?
Q
Lovely!!!
Q