Can we please merge all of the shabbat tags (or at least make them all synonyms of each other)?
List that I know of so far:
A tag search for "shabbat" (the only way I can think of for somebody to easily get to most of the Shabbat questions) currently shows the following:
If we want to sub-divide questions about Shabbat, this doesn't appear to be an effective way to do it. People will just go to the 341 and miss the 13 and 2 that motivated this question.
What we really need is hierarchical tags, so that we could tag specifically but register them all to also show up under shabbat. I don't know of a way to do that in SE. So I think if we're going to keep the sub-tags like oneg-shabbat that we also need to always tag those questions shabbat for findability. The tag wiki for shabbat should link to all the others (including ones that don't happen to have "shabbat" in their names, which my search missed), so that people looking for a more-specific needle in that haystack will have some starting points.
Monica Cellio's answer seems to have the support of the community (judging by votes). To summarize it, we should split shabbat into multiple tags, link in the tag wikis from the former to each of the latter and vice versa, and (and this is mainly where it differs from msh210's answer) require the shabbat tag on any question that has one of the finer tags.
Very well, what split?
I'm making this a community-wiki answer so people can chime in with how the shabbat tag should be split. What should the finer tags be? Edit the following at will, and indicate an estimate of how many questions each tag could have. Also indicate if the tag does not yet exist.