The first question makes me think of the old sayings “the devil takes care of his own” and “it’s hard to kill a bad thing”. One may ask that question of Fidel Castro too.
As to the second question, officially nobody, but most likely it’s the top two guys, Nicolás Maduro and Diosdado Cabello.
The worst scum of the earth have the best doctors who inject them with witch’s brews that keep them alive long past their expiration date. Hugo and Fidel being good examples but there are many others such as Leonid Brehznev