There's something about a long career on Broadway that makes lots of people think that their experiences are worth putting down in book form; over the years, I've known rehearsal pianists, dressers, chorus boys and stage hands who were busily scribbling their memoirs, most of which never saw the light of day. Now, one of Broadway's respected press agents, SUSAN L. SCHULMAN, has succumbed to the temptation. The result, Backstage Pass to Broadway: True Tales from a Theatre Press Agent, has just been published by Heliotrope Books. In Schulman's case, her efforts have been worth it; she's written a funny, sometimes shocking book about the things she's seen on Broadway for the past forty-plus years. (She got her feet wet in 1970 with Applause, starring the famously dyspeptic LAUREN BACALL, something that probably would have had most fledgling press agents applying for the night shift at Howard Johnson's.) Schulman is admittedly star-struck; there's a gosh-gee-whiz quality to many of her anecdotes, but her book is best when she's chronicling bad behavior: DAVID MERRICK's young wife NATALIE, LESLEY ANNE WARREN and JOHN DEXTER come off worst. If only most people who work in the opera industry were half this candid about their experiences, my job would be a lot more fun.