Answer:
I build up castles. I tear down mountains. I make some men blind, but I help others to see. What am I?
I only exist when you are here. Where you never were I can never be.
You throw away my outside you cook my inside. Then you eat my outside and you throw away my inside.
I get paid when I drive away my customers. What am I?
I may be made of metal, bone, or wood and have many teeth. My bite hurts no one and the ladies love me. What am I?
When is it bad luck to see a black cat?