I see no reason for different bathrooms, within the same home, to be cohesive at all. They're different rooms, in different areas of the house, and no one can view them at once. Have fun and do whatever finishes you want. Good luck with your renovation!

"Cohesive" is a feeling, a style sense, much more than it is about matched finishes. Nobody expects a kids bath to feel like the more luxurious master bath, even if they shared the same tile or chrome finish faucet.

Spots on faucets has nothing to do with.......anything? : ) All faucets will spot unless measures taken to prevent it. That means a quick wipe up of the bath when done, and equally quick wipe.......of said faucet. No matter its finish.

IMO bathrooms that are attached to bedrooms should be “cohesive” with the bedroom . A bathroom that is used for guests and the rest of the family should probably have some connection to the main living area where it is.

Agree that "cohesive" can be loose, like all traditional or all modern. Beyond that, each can have a personality. Powder rooms, in particular, are often under less functional pressure (no meds and makeup storage, etc) and can be a place to be more daring with splashes of design. Follow your vision!