Answer:
Tear one off and scratch my head, what once was red is black instead!
How can a pants pocket be empty and still have something in it?
A man goes out in heavy rain with nothing to protect him from it. His hair doesn't get wet. How does he do that?
You can't keep this until you have given it. What is it?
You do this into someone's ear when you want to be discreet.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.