lukaszthegreat: Whole ancient European world didn't really care about that. Greeks didn't even care about sex with goats (and other examples)
Comparing Christian "intolerance" to non-Christian tolerance is a major mistake - and maybe even dishonest.
Firstly, Christianity is not the same in time and space.
In time :
Christianity was not against homosexuality until say the 13th century. For quite a long time, homosexual sexual relationships were seen as a sin, but a sin of the same level as - say - fornication, masturbation, and generally speaking all non-procreative sex. As for homosexual love, Christianity did not care.
In space :
CATHOLICISM became less tolerant since the end of the Medieval Age, but Orthodoxy was always (and still is) fairly tolerant toward homosexuality. Same with Anglicans - which kept it at the (regular) sin level during most of their history - and with many "Protestant" churches. In any case, there was the tolerance of the church, and the tolerance of the people, and those were - and are still - different.
Second, for every one of your examples, I could find an opposite example of civilization "not liking homosexuals". China ? This is a Yang-Yang relationship - don't do it. Islam ? It is one of the few issues on which the Hadith are clear (and they are not very tolerant) ... but on the other hand Turkey and before the Ottoman Empire was extremely tolerant to homosexuality, being the first country to completely legalise it mid-19th century.
Finally, most often the "tolerance" is not clear cut. To give a simple example, in Rome being "passive" in the sexual encounteers was considered shameful, whereas being active was OK
In all case, NO civilization that I know of ever allowed homosexual wedding before the 20th century - so for any game in a "traditional" fantasy setting, this is a no-no for me - kills imersion. [If you make a non-trad setting, it is no problem for me. I would have had no problem seeing homosexual weddings in Morrowind].
My preference : no romance in my RPGs, thanks. I might like the universe / story / whatever, but I never felt any feeling for the characters, beyond "I like that guy/gal".