He can call it "blackmail" but at the root of the problem is the what he wanted to do with her was illegal, and if he did it he might get caught, so he didn't do it. The law deterred him.

No, I think you are really reading into that way too much, Ethan. After all, he evidently "dared" with Margaux, right? I think what Margaux mentioned about Dara being strongly assertive is the key here. Dara was assertive and strong despite living in a society that does not prepare kids for that, nor suspect them to be. In a youth liberated society, the great majority of kids would be like Dara, encouraged to be strong and stand up for themselves, and in so doing, would definitely keep the hands of anyone they didn't want on them off of them.

If Dara could learn to be assertive and strong like that in a non-youth liberated society, the vast majority of girls (and boys) would surely learn the same in a society that actively empowered youth.