I agree that the civil and religious elements of marriage should be kept completely separate. I wouldn't expect the RC church to marry gay couples but the state should allow civil partnerships for anyone who wants one, in accord with the democratically expressed wishes of the citizens, (assuming this might be the majority view.) I also agree that the muddy situation created by having an established religion contributes mightily to the difficulty in separating the religious and civil elements of marriage.
I am currently awaiting the judgement of an RC marriage tribunal on the annulment petition my exH brought but I have been divorced for a few years. The separation of the sacramental and civil elements of that relationship in the eyes is something made clear by every RC publication I read, and reiterated by the (truly lovely I have to say) officials I encountered during the annulment process. What this current controversy has given the Church the opportunity to do is to restate its view of marriage as (1) a sacrament and (2) for heterosexual couples, bearing in mind the miracle of Sarah, wife of Abraham, bearing a son.
What I hope it will do is nudge the church towards campaigning for separation of church and state, as the Catholic Church did in the US in the mid 19th century over the matter of religion in public schools. I don't think it does any church any good to be allied to a state, and it does the state no good either (see Ireland as an example). The RC church in the US pays its own way and is not beholden to any government for anything. MrsMeaner -- the advantages of separation of church and state cut both ways. 'Separation of church and state' isn't even what operates in the US; it's just a shorthand. The actual phrase was that government 'should 'make no law respecting an establishment of religion, or prohibiting the free exercise thereof.' The history of the UK (and its predecessor state, The United Kingdom of Great Britain and Ireland, would have been much less bloody if such an idea had taken hold there.
Aspirant, the RC church also excludes (officially at any rate) straight people not married in the RC church but in a committed relationship, or those who are divorced after marriage in the RC church but whose marriage has not been annulled and who have entered into subsequent committed relationships, the reason being that the principle of Catholic sacramental marriage is important to the church. And women, all women, are excluded from another of the sacraments (holy orders).
I think my own parish operates on a don't ask don't tell philosophy given the many gay cantors and the gay ministers of the Eucharist and the welcome for them and their children when it comes to sacraments, etc. I think the priest is impatient with 'churchianity'.
I agree with TheNewMrsC about the teminology used, though I can see that for Muslims who wish to practice polygamy, or fundamentalist Mormons who broke with the majority Mormon church on this issue, this might pose a problem.
The Catholic Church is not a democracy. Nor can you find an obvious line from what is in the Bible to what the Church holds on various issues. There has been a lot of theology under the bridge from the time the Bible as RCs know it (not the KJV, btw) was compiled to the present day. Not that there isn't a line, but a lot of thought in the theology and philosophy departments has gone into the development of the RC doctrine on most things.