As sleazy Hollywood bios go, Warren Beatty’s might’ve been a beaut, given his rollicking resume as celebrity and seducer. This one, though, is Dishtar. Amburn, a grump of a biographer, flogs Beatty when a tsk-tsk would’ve done, both in the bedroom (where he peddles rank gossip) and out. If, for instance, the Manson bloodbath earns as much space as Bonnie and Clyde, Shampoo, Reds, or Bulworth, that’s because Amburn seems to believe that the New Hollywood Beatty helped create brought it about. Criminally sourced, this piously joyless work is as stitched together as an inept ransom note cut from tabloid headlines. And Amburn thinks Town & Country was a disaster?