Eight mystery/suspense stories set in Los Angeles neighborhoods--with an even lower standard of quality than last year's mediocre Murder in Manhattan. George Fox (Amok) provides the best of a bad lot: ""Return to Venice,"" a competent, atmospheric reworking of a psycho-killer formula. Passable, too, are entries from Jon L. Breen (murder with a B-movie past full of clues), William Campbell Gault (a young Armenian shamus in search of a stolen rug), and Ray Russell--whose silly Hollywood murder-mystery (teeming with secret motives) is at least half tongue-in-cheek. M.R. Henderson's ""Dream House,"" however, is an interminable, implausible serving of gothic schlock, with plastic heroine terrorized by love-tormented psycho. Not as long, but even more slow-moving, is Vincent McConnor's inert, painfully old-fashioned ""The House of Crime."" William F. Nolan's ""Pirate's Moon"" is a soggy stew of psychic detection and cult-killings. And D.C. Fontana's ""Cut To: Murder,"" recycling an ancient show-biz plot, will remind you of any number of tired TV-mystery episodes. Dozens of classy mystery/crime writers capture L.A.'s tinsel-and-tawdry, beach-and-freeway world with vivacity and grit. None of them, unfortunately, is represented here.