A problem we have with a site on Christianity in general is that it will be difficult to frame questions which are truly good questions, conducive to good discussion. I like this idea:
"All genuine questions about Christianity are welcome" (Kramii),
but then I see this question:
"Do people who practice X go to hell?"
This is an example of a question which is likely asked genuinely, but needs to be improved before it can be answered in a StackExchange community - we are not a "confessional faith."
Obviously, it could be improved as: "Do Christians (or people from some specific Christian tradition) believe that people who practice X go to hell?" But even this is a far cry from a fruitful question.
As a Christian I would want to say: "This person needs a helpful, pastoral answer; e.g., does he have an understanding of grace, atonement, forgiveness? Does he realize that all Christians are in a process of sanctification in turning their lives to God, that we are cognizant that we all still, to some degree or other, live with sin - the church being a "school for sinners?" I would want to say: "We are told that God is the judge of ultimate things - and not we ourselves; please try to gain more of an understanding of Christ's love, and His gift of grace; and then consider the issue of God's justice, its place in human thriving, and its more ultimate consequences."
But my answer would probably, rightly, be down-voted - SE is a forum for informing, and not for providing pastoral responses. Yes, all those questions are relevant in the larger issues which frame this question. But no, we aren't here to be pastors or preachers.
I could probably respond, justly:
"Your question is better framed less specifically - e.g., 'what is the relationship between Christian practice and ultimate judgment - i.e., the issue of heaven and hell?' - as it can only be answered in the much larger context of love, grace, and justice."
But I don't think I'd want to give a lot of my time to these types of helping people re-frame their questions, and I'd be afraid that there would be many, many more such questions than people available to help re-frame them. Also, as a person of faith, I'd find this kind of answer somewhat insensitive-sounding - I'd be eager to answer it in a more pastoral tone, without banging down on the rules of the site regarding objectivity and properly-framed questions. But my "sensitive," pastoral response wouldn't be acceptable to others from a background which doesn't embrace Christianity - it would seem like pastoring, preaching, etc. etc., and not like a "just the facts" type approach.
It takes no expertise to genuinely ask a question about the Christian faith. But it can take quite a lot of expertise to frame a question in such a way that fruitful answers and discussion can ensue.
So I would suggest: before launching a site on Christianity, it is probably best to launch one on a topic which will likely attract more on-topic, properly-framed questions, simply because the topic is more specific: and thus I believe we would be better off beginning a site on Biblical hermeneutics, only later to start one on Christianity, with the hope that some of the expertise we have in Biblical hermeneutics is able to help us in moderating the site on Christianity. The site on Christianity will be a much, much more difficult and time-consuming task if the community here is really intent upon "getting it right" and assuring fruitful, objective, rational discussion and answers. There is simply so much passion involved and there are so many hot-button issues. And frequently, the most informed are highly passionate about the relevance of their viewpoints - on both sides.
In the end, the Christian site might be more of a place for "experts" asking good questions - with people warned beforehand that all questions are not equal, and the questions of newbies will very likely be re-directed to other sources. If it ends up becoming more of a democratic free-for-all with votes given based more on the answers we agree with, rather than the quality of the content - the site could end up a pretty sad place.
We must remember that when it comes to hot-button issues, many users will be much more profoundly motivated by the viewpoint presented, than the quality of the reasoning and the cogency of the answer. And most questions on value-laden issues are themselves value-laden in one way or another.