Just thinking out loud because I still don't know how tagging ought to work. (To me, StackExchange is just a fancy USENET. ;-)
Soldarnal's answer seems right to me. We need to focus on a tagging system that is optimized for finding questions and answers. When I starting thinking that way, I had a sudden insight:
Tags are observations.
They should be things that are painfully obvious to an expert in the field. Most sites, the tag is about the question. So my question at Judaism.SE was (apparently) about history tanach mitzvah derech-eretz-manners rebuke-tochacha. Once I looked them up, I agree: that was what my question was about. I didn't need to know the answer to see they were correct, I just needed to understand the tags and know what I had asked. (This is why tag wikis are critical. I had to Google two of the tags to find out what they meant. As a gentile, I just don't know the lingo.)
On Biblical Hermeneutics, the observations should be about the text, if that's what a question is about. That's why the vast majority of our tags are books of the Bible: the easiest observation to make is "where is the text from". Anyone can see that this sort of tag fits.
(There are a smaller number of questions that are about hermeneutics. These almost always carry hermeneutical-approaches and not a book tag. In these cases, our tags are about the question, just like anywhere else.)
Tags signal the desired type of answer
Just like c++ or catholic, we have tags that signal what type of answer the poster is hoping to receive. Oddly, tanakh has become one. Others are authorship, source-criticism, and (sometimes) textual-criticism. While you might be able to glean from the question that this is what is being asked, the tag makes extra sure. After the question has a good set of answers, these tags will be observations about the answers. These types of tags are somewhat less useful than the first since they limit the range of answers (often needlessly). Not being careful here can sink us into the meta-tag trap.
Tag should not be interpretations
I think this is where things get uncomfortable: what does it mean that I tag a question with inspired? It's not really an observation about the text (at least not an obvious on) and it's not really a signal to the type of answer being requested. It's more like one possible answer. I think these types of tags should be strongly discouraged.
Tags are by experts and for experts
We shouldn't shy away from using tags that require more expert observations. A question on Leviticus 19:17-18 or Matthew 18:15 is about reconciliation even though neither passage uses the word. Yes, it's also an interpretation, but it's really obvious to anyone familiar with the commentaries on these passages. If I want to find all the questions about reconciliation, I should be able to do that. This afternoon, someone asked be about a question on "biblical contradictions". It would be nice if I could have pointed him to contradictions.
I don't think we have quite enough questions to know if our single-use tags are going to be one-shot. septuagint has one question and lxx has another. I expect that these will be bigger tags in the future. nomadism probably won't be. But who knows? We have three deborah questions and I couldn't imagine there ever being more than one. I would probably leave them for now.