A small counterpoint to other answers, which seem to assume that offensive questions would also be poor quality. I think it would not be difficult to write legitimate (or seemingly-legitimate) questions that would probably be seen as offensive, or at least extremely uncomfortable, on any forum united around faith or ideology.
On Islam.SE, "Is Islam a religion of terrorists?" would certainly be closed as NARQ, but "What passages in the Quran justify terrorism?" wouldn't be. "Does Islam permit honor killings?" would be another prejudiced question, and it'd be easy to phrase that in an even more inflammatory manner with built-in assumptions, along the lines of the classic "Have you stopped beating your wife?". Aspersions, criticisms and attacks can be phrased in the form of a question. Any debate-team veteran knows that backwards and forwards.
One could construct similarly offensive questions for any major belief, simply by taking for granted that a certain prejudice is widespread, or keying in to unsavory aspects of the rules. Some pretty awful examples include, "A clergyman's been molesting children; how can we move him somewhere else without causing trouble for him?", or "Do the "beautiful captive" laws mean it is permissible for a Jewish soldier to rape Palestinian women?". Etcetera, etcetera.
Stupid questions, spam questions, diatribe questions are easy to deal with. They're off-topic; they get flagged, closed, deleted, burninated. But the format does seem to allow an antagonist to begin some very offensive interrogations, under the auspices of a factual Q&A.
Of course, there's not one-size-fits-all solution to such an attack. It's mostly more intensive mod and community response. A legitimate question can be rephrased more neutrally (and hopefully given some good answers!). A poster who's being deliberately provocative can be dealt with. But figuring out what the precise line is - what questions are challenging but OK, and what's intolerable and deliberately inflammatory - is something that'll be done by the community, on a case-by-case basis. And the bottom line is, yes, this could be a potential problem, and it's something to keep an eye out for.