No, don't put a piano in the foyer. While the foyer is roomy it's also a heavy traffic area. I can see that the kitchen is sitting off of it. You don't want to walk around a piano every time you go from room to room. Also, with all the heavy furniture you have, a piano in the entryway would make your house look like a furniture store. If someone plays the piano I wouldn't put it in a bedroom. If you just have to move it, switch places with the sofa on the opposite wall. It might even look better there. To define the two rooms adding chairs instead of an extra sofa would look nicer. It looks like you have four sofas? What I'd do is get a larger entryway rug. It helps to divide the two rooms and it won't look so empty to you.

You might not find this post either as you posted in the bathroom forum, lol. How about a sisal type rug?

Have you tried it angled from the front door toward the French doors, sort of leading one toward the hallway? Actually, I like the area without your console table, which I find a bit too chunky and contemporary beside the more delicate traditional stair newel and railing. Why not angle the rug and add a mirror centered 5' above the floor, with an armchair and floor lamp in that stair corner staged more as a reading nook?

I would suggest you use a rug that covers more of the foyer area...perhaps a tufted wool with and oriental pattern that sort of fits with architecture of your home...a smallish pattern with varied colors will hold up to entry traffic better than a solid...and at the same time a small runner can be purchased in the same color and pattern...I am not sure it needs to match the other rugs ...as the foyer seems big enough to be considered a separate room...with out pictures it is hard to be sure....but the foyer is the introduction to your home and sets the expectations for the rest of the house