It's been about a decade since I read any of them, though I suspect that they would think that patriarchy has a biological origin rather than merely a social one--the article in the OP certainly reflects such a view.
No. I'm somewhat more in line with Pope John Paul II's theology of the body--I think the danger of sexual objectification is omnipresent, but not insurmountable. I would say that radical feminists are engaged in reductionism, and thus go too far in declaring that sex is always coercive, but that liberal feminists naively overlook the darker side of sexuality and the ways in which social pressure plays a role.
It would depend upon the radical feminist--that would be very extreme, but there are probably some anti-natalists out there. Many are lesbians, though, which is a bit of a problem, given that they're effectively talking about sexual relationships between men and women without really having any understanding of what it means to be attracted to men. They tend to claim that only lesbian relationships are acceptable (which then overlooks abuse between women).
Oh, I don't think that there was an actual conspiracy. I'd say that it was the double standard between men and women, along with really bad attitudes towards sexuality and a touch of Romanticism, that led to the sexual revolution. The problem was that none of the issues that led to the double standard were successfully addressed, so if anything, we have larger problems with male entitlement and abuse than we did before.
Hence, the Patriarchy always wins, and the whole thing was subverted to be the opposite of what it was meant to be. That's the trick I was talking about. "Patriarchy" in feminist jargon refers to the social structures that lead to inequality between men and women, not an actual group of people. It's part of the leftist tendency to personify all sorts of social patterns. Useful shorthand, but disastrous if taken too literally.