Answer:
A dagger thrust at my own heart dictates the way I'm swayed. Left I stand and right I yield to the twisting of the blade. What am I?
I can be any color you can imagine. You see me in everyday life. Look around, you can probably see some of me right now. What am I?
I'm a ruler with 12 agents. Half of them work in the darkness. Who am I?
I go around a yard but does not move.
I am an instrument capable of making numerous sound but cannot be touched or seen.
Give it food and it will live, give it water and it will die.