I’m offered freely, asked or not, defended fiercely quite a lot. I may be strong, or quickly bend, depending on the mind I’m in.

It's like library but instead of checking out librs, you check out birds.

Great with soda, hated by camels. Can also be used to settle a dispute.

I dance without feet, I vanish, repeat. A candle may cause me, A bad wire may force me. I’m there, then I’m gone quicker than a snicker.

If you throw me out the window, you’ll leave a grieving wife, but drop me in the middle of a door, and you might just save a life. What am I?