Broadway musical “Kinky Boots” opened Thursday at the Al Hirschfeld Theatre with a flurry of glittering guests and shoes. “My dance shoes are always crazy. I have 22 theater shoes,” audience member Liza Minnelli told us before the show. Her date, Michael Feinstein, corrected her, “I’ve seen your closet — 1,000.” “I haven’t got room for that,” Minnelli shot back. Harvey Fierstein — who wrote the show about a factory owner and a drag queen, and has played women onstage — said there’s always drama in the drag world. “There’s always somebody prettier, there’s always somebody younger, there’s always somebody skinnier and always somebody with better hair,” he lamented. “I don’t think I’ve ever been the most fabulous drag queen.” Fierstein said he even had sex onstage years ago at La MaMa Experimental Theatre. Cyndi Lauper — who created the show’s music and burst into tears when she saw Minnelli — had less experience with such matters. “I don’t know? Chaps and a whip?” she said when we asked her definition of “kinky.”