1) Personally, I do not think all of the hardware has to match in finish. I have mixed chrome and brushed nickel and stainless in the same room. Personally, I prefer them to be in the same "family" (ie: silver colors), but that's just a personal preference. 2) I do not think that hardware finishes have a strong impact on whether a room looks dark or light. I believe that paint, floor color, countertop color, and vanity color have a much bigger impact on how dark a room feels because they fill up the space. 3) If you really like the contrast of dark wood (and/or dark granite or something) with the white, go for it. Consider using a light colored wall paint to keep the room from feeling too dark. I love the striking contrast of white and dark wood. 4) What other finishes would you like to mix in?

I spend a long time looking at faucets. I wanted a good quality faucet. I also needed/wanted a faucet that pull out. Otherwise, it would not be functional for me. I pull out, clean the sink etc. I wanted to be able to reach pretty far. For example, I fill a large pot of water with the pot on the countertop so I do not have to lift up the full pot from the sink! This meant that many of the high arc "cool looking" faucets were out for me. Many of the 'pro faucets' that have spring loaded head have very short reach, although they look cool. I also wanted to have the faucet in spray mode without holding down the switch. Many of the models require that you physically push the toggle to go into spray. As soon as you let go, it goes into stream. This was no no to me! I needed the spray so I could rinse dishes and vegies under the running stream of spray. I don't want water running in stream mode only... That left me very few models that looked good, was a good quality and still satisfied me. I ended up with a KWC Ono. You have to analyze how you want to use your faucet. Each person has different needs. Be critical and analyze what is important to you....

I dont have pictures that would show this, but ... My Kitchen has polished nickel faucets, and polished nickels pulls on one run of cabs. I have another area that looks like a built in hutch, and it has aged brass. My island has ORB. My range has PN and brass. My breakfast room has wrought iron and mercury. My fridge has old fridge hardware, i think it looks like brushed nickel? Maybe it will look terrible, lol. But my color scheme is very neutral and there is no pattern anywhere and I want an unfitted look. So I think it will work. Whether it will work for you depends on the style of your kitchen. Do you want unfitted, or sleek? Do you want it to feel old? I think mismatch is always more interesting if you can pull it off.

Satin nickel would be fine with the stainless sink. Chrome (my personal preference) would work just as well. Black for cabinet pulls and knobs will relate nicely to the black counters. You might find this guidance helpful: https://mariakillam.com/less-is-more-kitchen-or-bath-hardware/comment-page-1/ Here they have black cabinet hardware, a chrome faucet and brass on the fixtures.