I believe one of the best methods of keeping your guitar healthy is....Keeping it in it's case while you are not using it.

Its hard to actually decipher what your trying to ask in this post, but if your pickups have rust on them...I would look into getting new pickups.

I have no clue what material your bridge is so I can't recommend any chemical to help clean it, but a dry soft rag always works wonders.

As for the paint, I have no clue, its up to you.