F. Scott Fitzgerald obviously wasn’t thinking of Peter Schneider when he wrote that there are no second acts in American lives.After leaving his Disney prexy job in 2001, Schneider has refashioned himself as a legit director. Last year, he helmed tuner “Grand Hotel” at the Colony Studio Theater in Burbank. No one-hit wonder, he has now lined up a number of follow-up projects. This week, he begins rehearsals on a revival of Marc Blitzstein’s 1949 opera “Regina,” based on Lillian Hellman’s “The Little Foxes,” at Bard College. He has commissioned Valerie Martin to adapt her 2002 novel about slavery, “Property,” into a stage play, which he will workshop in spring 2006. And as for the really big time, there is the musical version of “Sister Act,” being written by composer Alan Menken, lyricist Glenn Slater and book writers Cheri and Bill Steinkellner. In a switch for Disney, the studio is licensing one of its hit movies and will not produce. Those duties go to Schneider, Michael Reno and Albert Poland. “Sister Act,” the musical, is under consideration for an October 2006 slot at the Pasadena Playhouse, with Schneider at the helm. Sometime thereafter, Broadway looms. Regarding his switch to directing, Schneider says, “My desire was to get closer to the artistic process rather than further away from it. Disney was a terrific experience, but as you go further up in the hierarchy, you become less involved in the creative process, and I found that less satisfying.” Directing for the theater actually brings Schneider back to his first career. In the 1970s, he was a helmer and assistant stage manager at such small nonprofit theaters as Playwrights Horizons, WPA and Circle Rep. While there, he met Susana Meyer, now the opera producer at Bard’s Summerscape Festival. She offered him the Blitzstein project, which runs July 29-Aug. 6 with Lauren Flanigan in the title role. If “Sister Act” is the biggest project on Schneider’s plate, then “Regina” remains his grandest departure. “I’ve never directed an opera, and I am truly fearful with excitement,” he says. “I don’t worry about the success of these things. I worry about the doing of them.” ‘Mambo’ problema Calling all play doctors! “The Mambo Kings” may be dancing to a new beat with an emergency rescue team of creatives. In talks to offer their help to the troubled tuner are director-choreographer Jerry Mitchell, book writer David Ives and lyricist-composer Jason Robert Brown. Earlier this month, “The Mambo Kings” opened to downbeat reviews in San Francisco, where it had its pre-Broadway run. The critics were pretty unanimous in not caring for the contributions of composer Carlos Franzetti and Arne Glimcher, who is director, lyricist and co-book writer with Oscar Hijuelos, who wrote the original “Mambo Kings” novel. The Broadway veteran of this group is Sergio Trujillo, who received high marks from the West Coast crix for his choreography. Even on paper, the original “Mambo” team looked like a risky proposition for Broadway success. There were too many debutantes. Also, triple threats like Glimcher always have a way of turning into singular threats to their shows. His major qualification for this tuner appears to be that he produced and directed the 1992 film version of Hijuelos’ novel. But movies aren’t stage musicals.