What Am I Riddles

Question: I am as thin as paper, smaller than string. I blow in the wind. What am I?

Question: A natural state, I'm sought by all.
Go without me, and you shall fall.
You do me when you spend,
and use me when you eat to no end.

What am I?

Question: All things I devour: Birds, beasts, trees, flowers.
I gnaw iron, bite steel.
I grind hard stones to meal.

What am I?

Question: I'm number three.
But I'm not a number.
I'm hot and cold at the same moment but not at the same time.
I'm number three.
But I'm not a number.

Who or what am I?

Question: I am something, a lot of people don't like me, including you,but I'm called upon anytime one is injured. I like playing with pregnant women, I'm a 5 letter word, and if my last letter is put before first letter, I become a name of a country, WHAT AM I? IF U GET THIS, U'RE INDEED A GENIUS.