Answer:
With sharp edged wit and pointed poise. It can settle disputes without making a noise.
What English word retains the same pronunciation, even after you take away four of its five letters?
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.
Only two backbones and thousands of ribs.
Upon me you can tread, though softly under cover. And I will take you places, that you have yet to discover. I'm high, and I'm low, though flat in the middle. And though a joy to the children, adults think of me little.
You use it between your head and your toes, the more it works the thinner it grows.