Essentially, yes. From my perspective anyway. It's my understanding that religions are all pretty absolutist: "This is true, this is the only way, and no other way is true." The old testament, for example, seems to be full of their god doing horrible things for reasons motivated by petty jealousy.
This is completely untrue. Several modern religious movements are incredibly open and accepting, including the Unitarian Universalists, Reform and Reconstructionist Judaism, and several (as far as I know, unnamed and not quite organized) liberal branches of Islam.
Perhaps this was true at one point, but religion has grown a lot. And as a Jew, the ones who pay the most attention to the "old testament," I can tell you that we don't base our traditions exclusively on that document. Most of our religious tradition actually comes from an extensive set of legal documents.
Frankly, I find this attitude a little surprising. Your summary of religions as "all pretty absolutist" is very ignorant. I'm not offended or anything, but you owe it to yourself to become a little more educated about a phenomenon that remains a major influence in the modern world.
For that matter, if the existence of intolerant strains rendered a movement unsuited to public discourse, science would also be disqualified. I mean, have you ever read Dawkins or Hitchins? Totally intolerant, elitist, self-satisfied dicks. Potentially, also brilliant dicks, but dicks all the same.
The only really civil way to conduct matters involving multiple faiths is to leave all faith-based matters completely off the table.
I absolutely disagree with this. I firmly believe that the only way to conduct matters civilly is to behave civilly. It doesn't matter what you're talking about - civility is an absolute.
This is partly where the "non-preferential" interpretation of the Establishment Clause in the First Ammendment comes from. And while the Establishment Clause was written in a different context for different purposes, I find that that the "non-preferential" interpretation is a worthy guiding principle when conducting matters of a public nature where people of different faiths are likely to be involved.
I feel like you're mixing your metaphors here. I'm not a government. I'm a man (or a woman, or a dog - this is the Internet, after all). I don't need to obey rules composed to regulate the activities of a government. I also can't arrest you or execute you (with due process) no matter how much evidence I have, and I can't penalize you for treason if you tell my next-door neighbor secrets about my bank account.
Now, here's where I think I agree with you, potentially. When it comes to matters of
policy, it's best to keep the discussion to shared ideas. If I say "my people have received a revelation that informs my behavior and I believe that this revelation should be made a matter of policy and dictate your behavior," well, that there is a mighty big, steaming pile of horse shit. This is why science is superior to religion in this arena; it represents, potentially, a shared language of true and false, from which one can attempt to extrapolate right and wrong.
That said, however, there is nothing wrong with using religion to invite discussion. To rephrase the example above, you could say "my people have received a revelation that informs my behavior - I believe that this revelation and the associated behavior is beneficial, and let me share it with you." That's fine. Potentially annoying, in the form of pushy evangelists, but certainly not amoral. Unless the criticism is explicit, it's no more critical than any other personal sharing. Do you feel judged every time someone says something informed by their diet, reading habits, or hobbies?
In conclusion, to make my argument more concrete, let me give you an example:
I am fervently pro gay-rights. I have several queer friends, and at one point I nearly killed myself campaigning against Proposition 8 in California (staying on your feet at a poling place in a hostile neighborhood for upwards of fifteen hours? I don't recommend it). Like Dave, my religious beliefs inform my opinion in this matter, but that's neither here nor there.
What is here and there is this: if someone were to say to me "I believe that Jesus Christ as an emissary of a higher power has condemned the behavior of homosexuals, and therefore gay marriage should be disallowed by secular law as a constant reminder that God wants them to become straight," I'd tell them that they were full of lizard poo, especially if they were less civil about it.
On the other hand, if someone said "doesn't God condemn homosexuality? How can you support gay marriage? Let's have a dialogue about this," I would be happy to talk to them long, hard, and into the night. The former is a condemnation, an attempt to mingle religion and secular law. The latter is just a statement of opinion informed by religion and an opening for conversation.