I would replace it with brass so it matches or is closely coordinated. If I were a potential buyer I would wonder if the non-matching faucets were a quick fix. I think this is one of those situations where keeping the finishes the same is more important.

Sumod- The medicine cabinets are simple wood frames with a cabinet-grade plywood back that just sit in the stud cavity. Because of the dimensions, the front of the frame projects about 1"+ beyond the finished wall. The medicine cabinet doors are also plywood with veneered edges and they are attached to the frame with standard cabinet hinges (Euro hinges). The mirrors are just 1/4" plate glass ordered to size from a glass shop and held in place with mirror mastic and a metal strip at the bottom that you don't really see. The guy who did the cabinets just made the medicine cabinets as part of the job. I don't know about the door brand...we live in a large metro area that has lots of door shops and the doors are just solid core maple doors with the center cut out and a maple panel held in with molding. They're not stained; they simply have a couple coats of clear spray lacquer.

Another vote for preformed showers not being in anyway perfect. I just ripped out a few and considered switching to tub and tile. The issue with ours is that they had foam for stabilization of the floor. Foam deteriorates and then the floor cracked. Mortar much better but just a reminder that one piece are not infallible. I have a 7 yo boy who has grown up in a tile and tub. The bathtub tile is not an issue. The grout around the toilet is a bit of one. But a big deal - no. I know things are regional but I haven't seen sheet vinyl used in a new home in a long time let alone a custom home. We built a super cheap rental house that has tile floors - but one piece showers. Vinyl rips, shrinks, burns, stains. If you have never had old vinyl, you need to look at some. Tile is pretty durable. Just to give you an idea of what this house is like - vinyl siding, vinyl windows, thermafoil cabinets, no crown etc. Interestingly, the worst cheap out we did was the showers and I wish we did better tubs and tile.

chances of popping those tiles off the floor or the tub in one piece are slim to none. and once you attempt it, you're committed. because if they break (and they will) now you have another missing tile in a more conspicuous spot to deal with. Those tiles were set in old school mortar. knock on them w/your knuckles. do they sound hollow or dense? if the latter, you'll never get them up in one piece. and let's be real about this, if you're going through all the trouble of taking up those extra tiles, buying new accent tiles to replace the ones removed, paying for all of that, then just take up the whole floor and start over! But it's moot because you'll never salvage those other tiles.