Janx: I think it absolutely essential that we not assert as objective fact anything about something which is imaginary. Without a real world example of mental domination, or without a real world example of a society that has long endured the reality of mental domination, I don't think we can assert anything about mental domination as factual.
For example, in a society with a long history of mental domination, there is no reason at all to suppose that having suffered a mental humiliation is going to be seen as less taboo than having suffered a physically humiliation. It's quite possible that society could stigmatize such victims as harshly or more harshly than victims of other sorts of crimes.
For example, on my imaginary world of Sartha players are often surprised to discover that mental domination is no legal defence in event that a player was unwillingly forced to commit a crime. To the people of Sartha, this makes perfect sense. After all, if mental domination could be used as a defense, then anyone having commited a crime could claim mental domination and it would be almost impossible to prove or disprove such accusations. Indeed, it's worse than that. From the perspective of the people of Sartha, the world is divided into people with the will to resist being mentally dominated, and those weakwilled people who are easily compulsed to commit evil. If a person has been mentally dominated once, then its a good indication that the person can be mentally dominated again. In the eyes of most of society, it's the person's own fault for allowing themselves to be dominated and that person can never be fully trusted again - even if they committed no crime. That they themselves might fail in this test doesn't occur to a lot of them, and sympathy for the mentally controlled tends to be very low.
Likewise, we can have no understanding of what it feels like to have experienced being mentally dominated.
Therefore, we are IMO on sound ground if we answer the question of "mental domination = rape?" only with 'undetermined'. Asserting that we absolutely know something that is imagined is exactly like something that is real can only lead to trouble. At the very least, how could anyone win that argument?