High above a 17-foot-deep pool filled with scuba divers and spare oxygen aerators, nearly a dozen acrobats swing across a steel-framed ship suspended from the ceiling as a 1,600-person audience gasps and claps. Below the ship, at O, Cirque du Soleil’s flagship Las Vegas show at the Bellagio Resort & Casino, a handful of old-timey aristocrat characters stoically walk off stage left. Backstage, the chaos is far less controlled. The aristocrat characters, called Comets, dart both behind and beneath the stage to circle around and reappear at stage right, sprinting past a shirtless colleague dancing wildly with a folding fan….