Been there done that (except perhaps the son’s wife banging thing - that I know of). The founder desesperately wanted his son as the boss and his daughter as HR. Except the son was stupid and mean, and the daughter was a bit brighter but even more machiavellous. The son made only yes-men stay under him, the morale went down everywhere. The company went bankrupt shortly after I left. I was not unhappy about the outcome.