Answer:
Many people own a copy of me. Without me the world would fall.
Open me, and you can't see me without a mirror. Close me and you can't see me at all. What am I?
Tool of thief, toy of queen. Always used to be unseen. Sign of joy, sign of sorrow. Giving all likeness borrowed.
It's red liquid but not liquid and it's not red. What is it?
I go around in circles, but always straight ahead. Never complain, no matter where I am led. What am I?
Give it food and it will live, give it water and it will die.