This is the approach I took in the beginning as a moderator; when we got posts that were too "Buddhist", it seemed we were expected to remind them that this is not a Buddhist site. Or, in the words of this post, "this is a Q&A web site, not a church".
But, after being on the receiving end of some textual abuse from irate answerers (e.g. being called "passive aggressive"), and doing a bit of digging and a bit of reflecting, I'm not so sure there isn't room for a bit of church-ness here.
While there are certain things we aren't designed for (pastoral therapy, for example), I'm not sure that we need take such a hard-line stance against being at least a bit Buddhist, and certainly against being communal. Here's some points to consider:
1. SE sites are considered communities.
As it says on the stackexchange.com front page:
Each of our 125 communities is built by
people passionate about a focused topic.
So, at the very least, we have to remember that this is more than just an encyclopedia, it actually is a community for people passionate about Buddhism. Just as stackoverflow.com is a programming community, I would suggest that Buddhism.SE is a "Buddhism community" (though not, perhaps, a "Buddhist community").
2. SE sites are designed to provide answers to real-life problems.
As it says in the 2-minute tour:
Focus on questions about an actual problem you have faced.
So, again, the focus is on helping people with their problems; Christianity draws the line on giving pastoral advice, but I would argue that this has to do with the fact that such advice is more likely to be opinion-based in Christianity. In Buddhism, on the other hand, there is much advice that can be given drawing completely from expert sources.
For example, photography.SE is full of real-world problems about taking pictures, not just abstract theoretical questions. SO is primarily a resource for people actually writing programs. Etc. Buddhism.SE should, by analogy, be a place where people actually practicing (or teaching, studying, etc.) the teachings of Buddhism should be able to get expert (meaning text-based, not guru-based) answers to their practical problems.
3. Stack Exchange is about making the Internet a better place.
On the company information page, it says:
Make the Internet a better place to get expert answers to your questions.
With this in mind, we have to ask what we are really trying to do; I think I can at least answer that we are not trying to create a second Wikipedia. So what does that leave us besides a sangha? Granted, we are not meant to be primarily a discussion forum, but we have chat rooms where we can discuss to our hearts' content.
What exactly would be the problem with allowing for a communal feel to the site? I think we've (read: I've) already managed to chase a few users away with our hard line; probably we've scared others from even posting in the first place. Look at the Judaism site's blurb:
Mi Yodeya is a question and answer site for those who base their lives on Jewish law and tradition and anyone interested in learning more. It's 100% free, no registration required.
Going by this, I would actually be in favour of site name like "Sangha" or something. No way I'd recommend "E-Sangha" (still have nightmares!) but just "Sangha"; we could be the Sangha of the Internet.
After all, a sangha is not about discussion or touchy-feely campfire pow wows; it's about getting support in our practice of the teachings of Buddhism, something that I think, on reflection, SE is uniquely designed for.