San Jose’s beautiful new California Theatre has been generating plenty of excitement in Silicon Valley and beyond. But a full house is dependant on much more than buzz, and for the California to be a success in the long run, it will be necessary for it to mount consistently high-quality presentations. That’s asking a lot of a city which recently saw its symphony replaced with a decidedly part-time ensemble, and which features an opera company which is still just beginning to come into its own.