I wonder if instead of putting the onus on the question asker, the "expert" answer should be the one to identify any doctrinal stances. There is a heck of a lot of theology that can be done without narrowing down to any particular school of thought, and its really only as you get into fringes that you need to identify a school.
For example, on the question "Why does God need people to have faith in him?" you can already presume an Arminian answer. The Calvinist may be debating whether the person who "chose" was chosen ante previsa merita or post previsa merita, but the question is beyond the Calvinist because God doesn't need to bring someone who is already going to come.
Furthermore, it is wholly legitimate for someone to ask this question without knowing anything about predestination, free will, merits, or grace. Indeed, I would be surprised if someone who genuinely wanted to know the answer would be familiar with these things.
Now, a really good answer is a different story altogether. Where appropriate, an expert should frame the relevant the discussion in historically accepted schools of theology. It makes total sense for the answer to say something like
Assuming that people have free will,...
(implication: an Arminian soteriology). A great answer would actually include the term, relevant links to Wikipedia would be even better. That way, the questioner learns how to ask what the terms are.
A true expert should be able to answer complex questions simply, aware of who will and will not agree with him. (I don't mean to brag here, but occasionally you'll see me acknowledge an issue, but then say "I don't want to deal with that objection here.") Putting labels is good, being restrained in what you claim if you are assuming a broad consensus is even better.
And, again, I don't mean to brag, but I think you'll see I strive to introduce theological terms (like kenosis in this one) so that the questioner then has a basis to refine the thinking and see what others have thought of the matter.
If we want the site to attract experts, then it is the answers that should be expert. The more sophisticated the questions, obviously, the better the site can be, but I would be careful about closing questions that can be refined.