I was thinking it might be easier to arrange the furniture around the piano, rather than the piano around the furniture. My furniture arrangement ideas are not set in stone.

well, if you want to use it to entertain guests, then the living room would be the appropriate place for it. is there enough wall space on the adjacent wall to the door to the mud room? I can't tell if there is 5'2" there or not.

if you do not entertain with it, then the office would be appropriste too. i would put it on wall that has no windows.

there is but it would be pushed up against a window :(

I was originally thinking in the formal dinning room (office) but think that might be too cluttered

Did you ever figure this out? I just started searching the same question this morning and our floor plan is very similar to yours. one wall fireplace/built ins, another wall windows, open to the kitchen with no wall, and the final wall is entry like in yours