What tile are you using? And are you tiling to the highest point everywhere else? I think it could look really nice tiled to the ceiling.

To the ceiling. And swap the oven and fridge.

To the ceiling, no question.

If you are opening up walls, I would get a taller window.

Also consider making that back wall of cabinets/counter just a bit deeper, to give the faucet a bit more breathing room between window trim and faucet.

Agree with others. You should also move dishwasher to the right of the sink so it is not in the prep area