There's nothing like getting fired from a cabinet position to enhance your worth on the lecture circuit. As government employes, cabinet members are not permitted to accept fees for speaking engagements. But now Joseph Califano, Griffin Bell, Michael Blumenthal, James Schlesinger and Brock Adams are marketable since their purge or departure from Jimmy Carter's fold this summer. New York lecture agencies are charging in the neighborhood of $5,000 for any of these men to speak to the college of your choice . . . If every television station in the nation decided to follow the example of San Francisco's KRON-TV, Washington would be awash in a sea of cameras, lights and microphones. Later this month that NBC affiliate opens a Washington bureau to broadcast news from the nation's capital five nights a week via satellite. George Osterkamp, former news director of San Francisco's KQED-TV, will head the new bureau that will include two reporters and two crews. Budget: about $500,000 annually . . . Julie Gordon, a local model who made good in Manhattan doing advertising spots for products such as Arid and Love's Baby Soft Body Mist, snares a role in a movie due next year to be based on the Son of Sam murders. Tentative title: "Demon" . . . "Good Morning America" news anchorwoman Margaret Osmer joins the Council on Foreign Relations staff as program director ending a 17-year television career. She replaces Marilyn Berger who left last summer to be chief correspondent for WNET-TV'S "City Edition" news show . . . At the Christian Science Monitor's Washington bureau, senior heads worry about a shortage of youth in top writing spots. Burau chief Godfrey Sperling Jr. and columnist Richard Strout are the two veterans who dominate the paper's capital coverage.