I think it looks better to switch (we did) if there is a logical place to do it. For us, the door knob into our bedrooms is unlaquered brass. We have a cased opening to the (short) hallway between the master bedroom and master bath. There are closets with mirrored french doors on either side of the hallway and a pocket door into the bath. The french doors, the pocket door, and the toilet closet door all are polished nickel and I LOVE them. On the other hand, I did chrome faucets in all other baths and they have brass knobs going in and they don't look bad at all. If you are doing unlacquered brass they will age fairly quickly (ours are already turning) and will be that soft bronzy brass in no time I bet.

I am not sure why you can't have a polished nickel single-handle gooseneck faucet. There are a number of manufacturers who make them. Just off the top of my head, without researching, I can think of Rohl, Hansgrohe, Kohler (particularly the Kohler Vinnata), and my favorite, Newport Brass. But there are others. Just do a search on various websites like faucets.com or homeclick.com. Here's a link to the Newport Brass single-handle pull-down kitchen faucet #94P in polished nickel. I really like their products. Though pricey, it's high-quality, and their finishes are top-notch. Sometimes Newport Brass has a long lead time though, but not always. But there are several other manufacturers who make polished nickel faucets. BTW, since you said you're not sure the difference bet. a pull-out and a pull-down, they are as follows: it's pretty much explained by their names. A pull-down faucet points straight down; many people feel they are more ergonomic to use. Some gooseneck pull-downs are very tall; you need to make sure you have the height clearance for them. I myself have a pull-out (the Grohe Ladylux Plus) which, well, pulls out instead of down. I don't find my pull-out to be un-ergonomic at all, and I like that it reaches across more towards the middle in my sink, rather than pointing down and closer to the edge. But that's just my taste. There are fans in both camps. HTH. Here is a link that might be useful: Newport Brass Kitchen Faucet #94P

We use Maas Metal Polish, but check first to see if your hardware was supposed to have a PVD finish which may carry a lifetime finish guarantee.

I just had this same dilemma last week for my build — the majority of my master bath is using unlacquered brass fixtures from Rohl. However, I was hesitant to use ULB in the shower as I just didn't think I would like the potential verdigris in a space that is meant to feel clean. Because of this, I opted for a polished nickel shower tower from Rohl. I know that mixing metals in rooms is widely accepted, but I wasn't sure if mixing metals for fixtures would be. Based on the floor plan of the master bath, I felt it would be totally fine and look appropriate. Right now I have a floor mount tub filler & wall mount sink faucets in ULB, shower trim in polished nickel. I will probably incorporate polished nickel into some light fixtures as well.