yes they can but they dont have to be.

If you want them to be but it's your choice!

Sure you can. It may be more interesting to do complementary but different for a more interesting and custom look.

Doing a whole house renovation is overwhelming. However, if you want to select the same sink and hardware for each bathroom, consider changing the finish on the hardware. Maybe one bathroom is chrome, anther satin nickel and the 3rd oil rubbed bronze. Or choose the same hardware finish but select a different style of cabinet hardware and sink faucet. There are many ways to personalize a bathroom.

Yes.