For chair scoot and sit space, I'd follow the guidelines for a rug - 4' all around. Then you want to be able to navigate around the table while people are seated, so add another 18" all around. Are you locating the table at the end of the galley? Maybe you could use a banquette on one side or in the corner https://www.houzz.com/photos/3rd-street-bungalow-traditional-kitchen-austin-phvw-vp~214425

also have uploaded a photo of our piano and mirror which I love. and I photo of our dining room light which I would also like to keep there.

Just some ideas to think about? Uber big arc light Round uber big leather ottoman Long floor to ceiling curtains with print or color 4 inch trim on either side of the panels hung between the windows. Art work set in the cubes similar but different, as in perhaps, musical instruments, African masks, Art Deco Lallique vases, anything that reflects You translated into art. Back cubes with mirrors and put puck light in the top of each for nighttime drama and to light the art work. A large Fiddle Fig tree as the trendy green this year. Possibly smoked mirror above the TV screen as big as the cut out. Bring it on.

Should have added, this is the existing layout: