Our top story tonight? Chevy Chase’s talk show is still on the air-despite scathing reviews, slipping ratings, and reports that publicists are thinking twice about placing clients on his Fox-TV program. Spokeswoman Betsy Hoffman says the network is ”pleased” with the show and is committed to seeing it through. But changes are in order: *No more musical interludes. ”We should have never had Goldie Hawn singing to Chevy,” says co-executive producer Steve Binder. The new plan? ”More remotes, more civilian-type guests and improvisational pieces.” Sound familiar, Dave? *No one has been canned -yet. Except for director Bill Davis’ exit and the defection of a writer who Binder says developed gallstones from stress, no staff changes are planned. ”Chevy isn’t a quitter,” Binder says in answer to rumors Chase might bolt. ”The war isn’t over.” *That’s not what the publicists think. Some are reluctant to subject clients to late night’s laughingstock. Says William Morris’ Cynthia Parsons, ”I saw Jennie Garth on recently, and he was making very bad jokes at her expense.” Binder defends Chase, arguing, ”They’re comparing him to people who’ve sat in the chair for years.” But doesn’t that mean he’s still not ready for late night, never mind prime time?