Answer:
I make you weak at the worst of all times. I keep you safe, I keep you fine. I make your hands sweat. And your heart grow cold. I visit the weak, but seldom the bold.
I am the tool, for inspiring many. Buy me in the store, for not much more than a penny. Don't overuse me, or my usefulness will go.
Slayer of regrets, old and new, sought by many, found by few.
What has wings, but can not fly. Is enclosed, but can outside also lie. Can open itself up, or close itself away. Is the place of kings and queens and doggerel of every means. What is it upon which I stand? Which can lead us to different lands.
What is the only letter in the alphabet that does not appear anywhere on the periodic table of elements?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.