Once Flash finally gets Barin focusing in the right direction, he becomes the King and leader he was always meant to be.
An early hint that the floaty-golden-robot-thing wasn't genuinely loyal to Ming? Its sensors were keen enough to pick up on Flash's whisper to Zarkhov, yet it didn't rat out Vultan for repeatedly bonking Ming's soldiers on the head during the Football Fight scene.
It is strongly implied, to the point of almost being stated outright, that Ming had been sexually molesting his daughter Aura—in public, no less—for years prior to the beginning of the film. When Ming uses his magic ring to force an orgasm on Dale in the throne room when Dale, Flash, and Zarkov first arrive, he asks Klytus, the head of the secret police, if he had ever seen such "responsiveness," to which Klytus responds "No, truly. She even rivals your daughter." It is thus implicit that Ming had been doing the same thing to Aura, presumably in front of his entire court, on a regular basis for years. Now consider Aura's personality, specifically, her hypersexuality, and her willingness to use sex to manipulate others. Those are both textbook responses to sexual abuse (n.b.: certainly not the only textbook responses, but still somewhat common).
With most Countdown of Doom situations, the last few seconds are the difference between life and death. However, Fridge horror kicks in when you think about the fact that was the last few seconds of prolonged environmental upheaval with the Earth. Really, Was there much OF an Earth left to save?
Although killing Ming stopped the assault on Earth, it wasn't actually Ming himself who caused the natural disasters in the first place: it was the "great god" Dyzan, who evidently considers smashing up populated worlds to be as entertaining as Ming does. And nothing the heroes accomplished has done jack-squat to prevent Dyzan from destroying the Earth - or Mongo for that matter - anyway, if Ming's god should happen to take offense at his worshiper's ouster.
In the scene where Kyltus and General Kala review Dr. Zarkov's memories, Kyltus, upon seeing glimpses of Adolf Hitler and the atrocities committed by his Third Reich remarks admiringly "Now he showed promise!" Nazi Germany and its Fuhrer instigated a World War that cost the lives of 70-85 million people, with well over 10 million of those killed as non-combatant victims of the Holocaust, and Klytus is only mildly impressed by that. This underreaction makes perfect sense when you consider that Klytus is from a galaxy spanning empire headed by a megalomaniac tyrant who routinely destroys entire worldsfor ''fun''. Ming probably kills 70 million people before lunch.