When you said above that status was the real reason LW-associates oppose legal polygamy, you were implying that these people are not actually convinced of these issues, or only pretend to care about them for status reasons.

If polygamous people where high status they wouldn't voice nor perhaps even think of these objections.

I think it's kinda weird that government is in the marriage business to begin with, but probably it is useful to have some sort of structure for dealing with the related tax / property / etc. concerns.

I tend to agree. Customizable contracts would be the best solution. This way we wouldn't straight jacket people into one size fits all marriage. Some people might like marriages where infidelity is grounds for divorce and the cheating party is penalized somehow. Some people might like marriages that have to be renewed every 10 years, to minimize any hassle with any potential divorce or allow a time out on the relationship. ect.

This would make everyone from the traditionalists to those seeking novel arrangements happy.