That actually sounds like a half decent solution. I wonder how it would play out in practice.
You guys are like 4 months too late. We did this and it wasn't used much and didn't provide much value. The reasons lke explained above were our intentions but once implemented, people just didn't use them much. Here, take a look:
I feel like the solution in this case and at this size is just to ask people to stop as "building for where you are going might not be the best strategy for where you are currently at." But now I see a puzzle and I want to think about it more. In keeping with three tags and trying to keep things simple for the user, would setting a preference for community tags attack the issue? For example you have Abe, Betty, and Charles. You like Abe's tags but because he thinks differently but doesn't check hubski that much so his are rarely the community tags. Betty's are good and they are what other people commonly tag as too. Charles' tags are also followed by the community but they are groupthink-y a lowest common denominator. A drop down on their profiles could set their community tag priority as low, medium, or high, with each step up overriding the others and everyone being medium by default. This way I could follow a users 'personal tags' without the user subjecting the community to their personal critique. Two problems with this: I don't know enough about how community tags are changed to be able to say if this idea really fits and, while I don't see exactly how, it would seem that a system like this could lead to a kind of cabal or 'back room' of hubski that's not in line with transparency. EDIT: This might be too far out there but that community tag could override your filter preferences. So if Abe sets a tag I follow on a post with a tag I don't, it comes into my feed. If charlie sets a tag I follow on a post with tags I don't, it still doesn't come into my feed.
Once tags have names attached to them the system could be gamed in terms of organizing witch hunts, but that seems like a pervasive threat any way. An alternative to the above would be to allow you to prevent individuals from tagging your posts in the same way you can prevent individuals from commenting on your posts. This wouldn't necessarily require names to be attached to tags since, in a town as small as hubski you could probably pinpoint the perpetrator, but it would be aided by named tagging.