Look, the long and short of it is that a Succubus functions on the same base mechanic as a Vampire.
Vampires need blood. Either this requires donations, or assault. (there's a whole writeup for how the Vampire's Slam attack works and how they take blood from another against their will)
Succubi need sex energy. Either this requires voluntary sex, or rape(aka: non-con sex).
As D&Ders, we're sort of used to violence. But when you combine violence and sex, you get rape. Noone really wants to engage in rape at the table, especially when it is done by or to a player. There might be a few people willing to do so, and you might get a good player who wants to play this class but never uses their power against the unwilling (which IMO, would be a very interesting character concept: a Succubus who'd rather starve and die than force another into sexual activity). But those things are rare and it's just as likely that you're going to find 4 players for whom rape is incredibly distasteful and uncomfortable, for every 1 that might be willing to engage in it (and among those people you're likely to find some real weirdos).
Your examples of other forms are mind control are poor, because none of them imply sex. If sex were to happen after being mind controlled, that's 100% on the player. Your rules on the other hand explicitly call for sexual activity (even if as little as a kiss).
Personally, I'd so away with the requirement for actual physical contact right off the bat. Jump straight to "can syphon off Sexual Ki from 5 feet" and make the distance increase as the character increases with level. If voluntary sex wants to happen, fine. But this way you rules don't call for physically retraining a person and sexually assaulting them.
Yes, I realize your text functions like the Succubus stat block, but the succubus is a monster that players kill. Your player is a player who presumably, doesn't get killed for simply existing in the mortal planes.