Was there any historical culture in which same-sex marriage was common or accepted? I can’t think of one, Christian or otherwise (though I can think of a couple of examples of same-sex people got married by subterfuge).
Homosexual activity cannot result in biological children so there was really never any society that considered anything like homosexual marriage until our own. The main reason for marriage was to control sexual unions and the children who might result from them. In societies which had marriage (many had no such concept) homosexual marriage didn't make much sense.
The wikipedia article on historical same-sex unions mentions that some cultures had rituals around cementing homosexual relationships but those wouldn't be considered the same as marriage, they'd be more like any pre-sexual / pre-relationship rituals. Marriage typically is about the sharing of finances, responsibilities, the raising and rights of children, etc. And none of the examples in the wikipedia article on historical same-sex unions concerned any of these.
I'm not sure that the points you're making about shared finances are particularly important, or even true, based on this. But I'm not a historian.
In this account of the relationship between two men they are termed in quotes as "husband" and "wife" to imply sarcasm . They were not literally considered with seriousness to be married by their society the way we consider men to be able to do to each other now.
Marriage, in societies where it existed often served two functions: binding families and providing for the legal rights of children. Unions of lovers did not do either of these.
Many ritualized unions of a same-sex variety in history were of the latter type and those of the former would not likely have been seriously recognized by the outward society. There isn't a strong record of that anyways.