Sexual liberation cannot occur on a broad scale while wars rage, while nuclear waste accumulates, and while forests are clear-cut. Sexual liberation can not occur while people are oppressed for the color of their skin or the cheap labor they can provide. Sexual liberation requires total liberation and the broader population is only sexually liberated to the extent which they are liberated in every other metric of freedom. There can be no liberation without sexual liberation.
This is a leap too far. In almost all human societies people tend toward monogamy or serial-monogamy. We want a permanent connection with a mate around which to form families. It is unsound logic to say that there can be no end to oppression nor hope for the planet unless we abandon that basic social framework. (family>tribe>community>state>humanity)
I also think you did too much hedging, caveats and disclaimers.
And, in the final analysis, the men's rights crowd should recognize that even the raping of men (at historically unprecedented levels within the United States of America ) is, actually, the result of an oppressive patriarchal system. This is undoubtedly a feminist issue. Feminists don't want their husbands, fathers or sons raped any more than they want their sisters, daughters or mothers raped.
There is most definitely doubt over whether rape of men should be a feminist issue. Individual feminists may care equally about their brothers, husbands and sons, but except to the degree that your wellbeing is tangentially related to the wellbeing of women,
feminism doesn't care overmuch about you and shouldn't. The only useful and realistic definition of feminism is "advocacy for women". There's nothing wrong with that, but expecting feminism to take care of you and your sons is both foolish and presumptuous. If you believe that women need greater advocacy, by all means be a feminist, but if you're doing it thinking that the end goal is equality for all, then you're fooling yourself.
The raping of men may very well be a result of patriarchy, but that doesn't mean that women should be the ones solely responsible and entrusted to fix it.