Barbara Stanwyck embodies multiple roles—a stage performer, a commanding personality, royalty, and a suspect in two murders—and it manages to fit a considerable amount into a pleasant and energetic ninety minutes. The local opera house has faded from its former glory as a place for Verdi and Puccini performances, which upsets “Lolita” (Victoria Faust), who isn’t pleased that “Dixie” (Stanwyck) is now the headliner wi…