Answer:
I suck.
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. What am I?
I produce wool and spit a lot
What force and strength cannot get through, I with my unique teeth can do. What am I?
I have feathers that help me fly; with head and body but I'm not alive. Very skinny and a fixed length how far I go depends on your strength.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.