By GARY DEEB Bouquets, brickbats, and other pertinent scraps from the cluttered notebook of a TV critic: At least four new shows already appear headed for the Nielsen scrap heap after just two weeks of the 1975 fall prime-time TV season. Doc, Mobile One, The Barbary Coast, and The Montefuscos are as good as gone. None is expected to be around by January, and at least two probably will be dumped next month. The shakiest of the bunch is Doc, the low-key Saturday night CBS comedy starring Barnard Hughes. Coupled with the disappointing ratings of The Jeffersons, Doc is threatening to nullify the long-running CBS domination of Saturday viewing. The Jeffersons and Doc are harming the ratings of the CBS shows that follow - Mary Tyler Moore, Bob Newhart, and Carol Burnett. Look for CBS to bump off Doc within the next few weeks, reschedule The Jeffersons back to their old 7:30 time slot, and bring in a blockbuster - probably M*A*S*H - as its new Saturday night leadoff program. Meantime, All in the Family continues to thrive in its new Monday night time slot. Last week the show drew its highest rating in years - 55 per cent of the viewers. Saturday Night Live with Howard Cosell, ABC's new variety hour, is every bit as fraudulent as its host. The opening item on the premiere of this "live" show was a prerecorded, lipsynched number by the Broadway cast. of "The Wiz." Later we saw a British teenybopper group called the Bay City Rollers. They were live, all right. But their words and music were prerecorded and again lip-synched. In fact, even most of the songs actually sung live on the program employed pretaped orchestral arrangements. A house orchestra may have been hanging around somewhere, but it never was in evidence. Otherwise the Cosell show featured a brief walk-on by Frank Sinatra, who kissed Cosell on the cheek; a short chat with Paul Anka, whom Cosell bussed on the cheek; an opportunity for Jimmy Connors, the tennis star and pampered poodle, to prove he can't sing a lick (no kisses were exchanged); and some swell glimpses of celebrities in the audience (including at least three shots of either Carol Channing or a female impersonator). Police Story, the often brilliant Tuesday night anthology of cop dramas, is having some problems in the ratings this season. So far, it's running third to Switch (the Eddie Albert-Robert Wagner caper series on CBS) and The Rookies, the moronic piece of trash on ABC. So NBC and Columbia Pictures TV are bringing out the big guns to push Police Story. Joseph Wambaugh, creator and guardian angel of the series, says Tuesday night's episode, written and directed by Robert Collins "represents an important television victory in our ceaseless attempts to portray reality." Wambaugh adds, "I can promise you the most credible portrait of a cop killer that the medium has ever seen. Don't expect a television ending. This is police life as I know it. It is real and true." Joe's emergence to promote Police Story would seem to indicate that he has buried the hatchet in his dispute with NBC vice president John McMahon and Columbia v.p. David Gerber. Wambaugh had charged that the premise of Joe Forrester, a new NBC cop show, was an utter ripoff of his "Blue Knight" novel. Morally speaking, he was 100 per cent correct; but from a strictly legal viewpoint, he probably had little to stand on. And The Edge of Night, a CBS day• time staple since 1956, is moving to ABC. Beginning Dec. 1 the slow-moving, mind-numbing soap opera replaces You Don't Say, a game show, in ABC's daily 3 p.m. slot.