No matter how civilized we are and how much society has curbed violent behavior. Human beings still have the same genes they had 10,000 years ago. Our bodies are designed to have a certain amount of physical stress and violence in them. We're designed to run from jaguars and fight to defend our territory.
I don't know much about the music business, but for just general advice for someone trying to create things, as simple as this sounds, I think the best thing you can do is constantly try to improve upon your work. Always focus on that first and foremost, and leave everything else (marketing, image) completely secondary. Obviously, easier said than done when you're trying to make a living, but if you can move along those lines and earnestly try to make things that you really enjoy it can only benefit you in the long run.
Also I can come up with new bits - people yell stuff out and it's a new subject or a subject that I've been thinking about that I haven't done onstage yet and I'll just run with it.
