The venerable and venerated octogenarian has put his company through self-inflicted turmoil with the abrupt ouster of actor Tom Cruise and chief Tom Freston. Media baron now lords over 2 fiefs: Viacom (Paramount Pictures, MTV Networks) and CBS (UPN, Infinity Broadcasting). Boston-born tycoon split operations in January to stimulate languishing stock. Viacom shares down 13% since split, but CBS up 9%. Hopes for rebound in movies: bought DreamWorks live-action studio for $1.5 billion from founders David Geffen (see), Steven Spielberg (see) and Jeffrey Katzenberg in February. Son of drive-in-theater owner now controls 1,400 screens; daughter, Shari, president.