I certainly find quality discussions about such topics interesting and worthwhile, and consistent with the mission statement of advancing rationality and overcoming bias, but I'm not sure if the way you define your proposed topic is good.
Namely, you speak of the possibility that "bias towards monogamy is built into human brain chemistry," and claim that this bias is "certainly built into (Western) society." Now, in discussing topics like these, which present dangerous minefields of ideological biases and death-spirals, it is of utmost importance to keep one's language clear and precise, and avoid any vague sweeping statements.
Your statement, however, doesn't make it clear whether you are talking about a bias towards social norms encouraging (or mandating) monogamy, or about a bias towards monogamy as a personal choice held by individuals. If you're arguing the first claim, you must define precisely the metric you use to evaluate different social norms, which is a very difficult problem. If you're arguing the second one, you must establish which precise groups of people your claim applies to, and which not, and what metric of personal welfare you use to establish that biased decisions are being made. In either case, it seems to me that establishing a satisfactory case for a very general statement like the one you propose would be impossible without an accompanying list of very strong disclaimers.
Therefore, I'm not sure if it would be a good idea to set out to establish such a general and sweeping observation, which would, at least to less careful readers, likely be suggestive of stronger conclusions than what has actually been established. Perhaps it would be better to limit the discussion to particular, precisely defined biases on concrete questions that you believe are significant here.
I think I grouped my ideas poorly; the two kinds of bias you point out would be better descriptions of the two topics I'm thinking of writing about. (And they definitely seem to be separate enough that I shouldn't be writing about them in the same post.) So, to clarify, then:
Topic 1: Individuals in industrialized cultures (but the U.S. more strongly than most, due to religious influence) very rarely question the default relationship style of monogamy in the absence of awareness of other options, and usually not even then. This is less of a bias and more of...
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