Over on the Skeptic site, they have a rule that all answers include references to sources. It's a hugely different site than ours, so such a rule isn't necessarily appropriate here. But there are answers that draw on knowledge outside of the texts in question that probably need to cite references in order to avoid inexpert opinions.
Looking through a sample of answers, I'm struck by how many people already reference commentaries, Wikipedia, dictionaries, professional research, multiple translations and so on. If we instituted a "cite sources" rule, I think the majority of us will continue operating as normal.
However, there are some answers that don't use outside sources and aren't particularly accessible to those outside of the particular hermeneutic tradition assumed by the author. Unlike, for instance, the Jewish Life & Learning site, we don't have a common heritage to draw upon. The only thing that holds us together is a common interest in the Biblical texts. If we don't take steps to educate others about our traditions as we answer questions, we risk speaking past one another.
Of particular concern is determining if answers represent or reflect expert opinion from the particular hermeneutic approach being used. If I say "this passage means such and such", there's no way to know if I'm speaking with authority or not. But if I say, "Augustine says this passages means such and such", anyone familiar with Augustine will be able to decide if it's authoritative or not. Further, we can evaluate Augustine's reasoning directly.
Should we require (or strongly prefer) answers to cite their sources?