A growing favorite in Pravda, official handicap sheet of the Soviet Communist hierarchy: mop-haired Mikhail A. Suslov, 58, party braintruster and veteran member of the Presidium. Three times last week Pravda quoted lengthily from "important" Suslov speeches. Unsurprising contents of all three: fawning eulogies of steady booster Nikita Khrushchev. . . . Wealthy Pasta King Giovanni Buitoni's money is in his tummy, but his heart is really in his throat. The 68-year-old macaroni maker is going into opera, he says, to "fulfill one of my fondest dreams," will sing the basso profundo role of Don Basilic in a charity performance...

