- Remove the provisions in the proposed legislation which prevents groups of people or blood relatives from marrying.
The state cannot assume a neutral position over the morality of homosexuality while it continues to make obstructive moral judgements about other harmless relationships between consenting adults.
You're being disingenuous there. Blood relatives are forbidden from entering relationships for valid health and safety reasons - the offspring from an such relationship would be genetically flawed as a result. To claim that it is "harmless" is to ignore medical science which has proven that it is indeed incredibly harmful.
Why groups of people can't marry though, if you were to ignore the moral aspect I suspect there are logistical issues to address - how does this work when one member of the unit wishes to divorce? How does the Relationship Property rules apply in this case? It would be an absolute nightmare and not one I suspect any government feels like addressing.
With regards to blood relatives health and safety reasons, there can be problems for offspring. It's not always a given. If it was human success at animal breeding would not have been anywhere as successful as it has been, what with blood lines being used to breed desired traits into the various species we depend on.
With groups of people marrying what 'moral aspect' are you referring to? After all Islam and many millions of moslems have been, and still do practise multi partner marriages. Admittedly just one man, many wives. But it doesn't have to be that way does it. It could be one woman, several husbands, several women, several husbands, etc...
As to the legal aspect, and separation/divorce, in the end it is a legal situation, and we can make laws to govern such circumstances, just like we are for SSM. There is no biological reason to prevent multi partner marriages, and we have already seen what happens when 'morality' is used as an argument to prevent people living the way they want to with whoever they want to...