Wouldn't both profanity and stutter come under speaking? (and profanity come under either online-interactions or communication for written?) I don't think we need specifics in regards to both aspects of these. I would happily untag the questions under these tags, but it'd be nice to have to input on this also.
Every topic on the site falls under the the tag "interpersonal"... Which is blacklisted for that reason. Arguably the same could be said of communication, since the vast majority of questions here concern communication, including the top tag conversations...
...Which is to say, you could get rid of pretty much everything here except for communication and the various locale tags.
Surely that doesn't sound like a good idea?
A tag is too narrow if there can ever only be one question in it. In practice, a tag is just noise if, after some reasonable period of time, there is only one question in it (in fact, the system deletes such tags after 6 months unless someone took the time to write a wiki for it - so, uh, don't waste your time writing wikis unless you know a tag is gonna be useful).
Beyond that, narrowness stops being so important; what matters is that the tag actually applies to the question it hangs off of: using the profanity tag on questions that happen to mention the profane in passing is a waste, but if folks are asking questions about profanity, surely a profanity tag is warranted!
The guidance on the sidebar of the Ask Question page includes these two bullets:
use tags that describe things or concepts that are essential, not incidental to your question
favor using existing popular tags
If you start with the most popular (likely broadest) applicable tag and keep going until you can't find anything else essential to the question or hit the limit of 5 tags, a set of reasonable tags should emerge fairly quickly (thus making it easier to pick relevant tags for future questions). Until that happens - until this site can be said to represent a solid cross-section of knowledge on interpersonal skills (without laughing) - then worrying about tags being too narrow is not a good use of your time.