What Am I Riddles

Question: When I am released to the wind,
you look away and you pretend,
but away your friends I will send.

What am I?

Question: Had by few but treasured by all,
I'm on the inside and outside and I make men fall.

What am I?

Question: Under pressure is the only way I work,
and by myself is the only way I'm hurt.

What am I?

Question: I am a digit, but two of the ten.
Two of me make a promise.

What am I?

Question: I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter.

What am I?