Answer:
By myself, I'm practically nothing. Worthless as a leader, but when I follow a group, their strength increases tenfold. What am I?
I am the kind of a tree that is carried in your hand. What am I?
What has many teeth but can't bite?
I turn everything around but I cannot move. When you see me you see you!
What is full of holes but still holds water?
I always have to work with something in my eye. What am I?