if you feel a sensei should not date any students, then of course you feel a single minister, or church board member, or choir director shouold not date parishoners. Also, there should be no dating anyone who owns a business. Oh, and no dating anyone who owns a market if you shop there. Hmm, if you listen to a musician, you cannot date them. Also actors whose films you like.
The sensei does not have power over anyone who is not in desparate need of counselling, and those folks can create a sense of control that is not there. Yes, abused wives who do not leave their husbands need to be repeatedly told to leave, i know i was told and told until he almost killed me. But it was not his fault i stayed, he took advantage of an illness in me, and that is why i got counselling.
from what i hear in the annon. statements, they were not forced in any way into a relationship, they willingly went, then got dumped, and now have problems over it. As for the touching issues, well, this is a MA, and in another long thread we covered why we as women don't want males afraid to train with us. if it is accidental, then grow up or get out, contact is inevitable in MA. If it is purposeful (and be sure you know the difference) then follow my earlier advice.
Men and women can WILLINGLY enter into relationships because power and authority are seductive. But that is not different than entering into the relationship because a great figure or large income is attractive. But be responsible for your actions and don't blame the previous object of your desire when it does not work out. If you think you will have a problem facing someone in the dojo/work/church etc if it falls apart, then don't start. But none of the folks were forced into a relationship, thye are just complaining that they don't think others having them is fair.
if you agree that it's not fair to other sutdents for a sensei to date someone he is teaching, then of course he can't teach his children. tell that to O Sensei. I just think if we as women (as the complaints came from women) want to be taken seriously, we need to be responsible for our own actions. there is nothing about the first sensei mentioned that implied he took advantage of his position (date me or i'll kick you out), the women all flocked to him. It's only a dojo, and it IS HIS. Move on with your own life. He may be a cad, he may not, but so what. if you want to learn from him, stay, if not, leave. it is childish to expect someone else to change to suit you; it's his dojo, find another that you like better. If he is as bad as you say, and all vote with their feet, he will change or close the dojo.
if you want to limit who can date whom, then it really needs to be no dating anyone within the dojo. otherwise the lines are too hard to draw, take it from me, the military is constantly having problems over this. You may be both kyu students, but what happens after he passes shodan. Or is shodan and first kyu worse than 6th dan to shodan? how about first kyu to 6th kyu? get real, we're all adults and need to stop worrying about who is dating whom.