Yes, I definitely think so, its one of the only ways to make talking about sin on topic.
As a Catholic, I know that is totally bogus, that some sins are much worse than others, some sins cry out from the earth for vengance etc... Some sins scandalize the youth... So you'd have to be clear on what mainstream/fringe group you're asking. But it should almost always be on topic and asks me if you're talking about Catholicism.
BTW, I'm also trying to start a Catholic Culture site on Area51 where that kind of stuff will definitely be topical, even without a specific dogmatic reason for asking. (not to do a shameless plug or anything)