Dictators can do what they want, but they can’t overrule the laws of economics. If the economics state you are done, you’re done. The best they can do is flee from their rule with the billions they stole from the people.
Sometimes. Sometimes not. Maduro is still there. All they have to do is be willing to kill anyone in any number. Xi ain’t letting go any more than Mao did. He’s got the guns to do it.
Castro seemed to do ok.