I have nice brass hardware but wanted brushed nickel. Is there a faux finish? Or can any faux finish be applied to cabinet or entry hardware?

I've had good success with the "textured" metal spray paint on cabinet and drawer knobs. A clear coat over the paint will help the finish last. Be sure to clean and degrease the hardware very well. I never tried it on door knobs and such, but it doesn't sound like it would be very durable.

Brass is a notoriously poor base for paint and the like. I would expect anything you do to begin peeling off quickly, and certainly wearing off where you handle the hardware. Brass is, however, a very good base for metal plating. You'll have to remove the hardware, and remove any trace of lacquer which was probably applied to it, and then send it out to a plating company. There are a variety of metals which they can plate onto the brass, and a variety of finishes for each of the metals.