Answer:
I'm as simple as a circle worthless as a leader; but when I follow a group their strength increases tenfold. By myself I'm practically nothing.
What can travel around the world while staying in a corner?
I am a band that does not perform, sing, or act. What am I?
What can you catch but not throw?
I may only be given but never bought. Sinners seek me but saints do not. (one word).
I always murmur but never talk. Always run but never walk. I have a bed but never sleep, have a mouth but never speak. What am I?