You've got a tough crowd, there, Ernest--the rules you've set up have something in them to exclude almost every one--the requirement for instrumentals between numbers is a particular killer for acapella singers----and the requirements for doing familiar numbers exludes ethnic performers and "world music" types, as well as anyone who has developed a program of historical or nostalgic material--

As to the restrictions on original material--one of my students told me this story: A new, nameless band asked one night to play at their neighborhood pub--the group only had a few songs, all original--but when they played them, the crowded begged to hear them again--the group later named themselves "The Cure"--

All in all, it's best to let people do what they will--