Answer:
Kills the bad ones and the sad ones. Tightens to fit, so one size fits.
Always old, sometimes new. Never sad, sometimes blue. Never empty, sometimes full. Never pushes, always pulls.
I can be used to type and point you see. But don't forget, you can count on me. What am I?
I am a precious little thing, dancing and eating all the time. Watch me from a distance, so you can feel my warm and gentle love. But don't come to close or my next meal you could be!
I march before armies, a thousand salute me. My fall can bring victory, but no one would shoot me. The wind is my lover, one-legged am I. Name me and see me at home in the sky.
What never gets any wetter no matter how hard it rains?