Hmm, I think those are pre-existing pathologies in society that free-love folks have worked really hard both to prevent—by empowering women, by frowning upon non-lesbian couplings, by talking extensively about informed and enthusiastic consent, and by fostering cross-gender friendships the monogs were suspicious of—and to reduce the harm from, for example, with birth control, condoms (and strong norms against not using them), and by socially supporting single motherhood. Sex parties in free-love circles very frequently have strict rules against alcohol, while many serial monogamists can only copulate when intoxicated. So I think you're probably mistaken.