1. In some, the theme was "this is the martial arts and the ma are about 'power', thus students should learn to acquire their own power". Unfortunately, to me this sounds like the rationalization of predators, be they sexual or otherwise. Aikido is about the proper use of your "power" (KI) to defend yourself and keep yourself safe. To do anything else is a misuse of KI.
If you think I am rationalizing predatory behavior, you are severely mistaken. Chasing an unwilling student is obviously inappropriate, but an initial proposition is not predatory behavior.
Power does not equal Ki, but let's argue about that later.
As to any "Sensei" dating a student. If they are both the same approximate age and meet outside the dojo and are respectful of each other, then "possibly" it is okay. Otherwise the "Sensei" is on an ego trip and their ticket needs to be cancelled.
Why is that "possibly okay"? If some crazy student worships their teacher and can't manage to say no inside of the school, why should their attitude change outside of the school? Does the teacher's ability magically depart once he or she leaves the sacred confines of the dojo?
And why are you bringing age into this discussion?