There are some who may quibble with Santa Barbara High School's iconoclastic Drama Department head Otto Layman that he sometimes chooses material that might prove too challenging, too risque even, for a high school production, but he plows ahead anyway; he knows his stu-dents perhaps even better than some of their parents. At least, Otto really, believes he knows what his thespian charges can do and which among them will rise to the occasion. And he rarely misses. His latest challenge is Cabaret, the musical, and the first of what Otto presumably hopes will be a yearly "Summer Stock" production