It might help to think of these things as thematic listening clusters. As you noticed, there are a variety of different kinds of genres. Some are musicological, some are historical, some are regional, some are political. We like all of these. If you look for "indie" you'll see that we do have genres for a lot of local scenes. And those scenes have widely varying character, so I don't think it would be an improvement to combine Vienna indie and Michigan indie and Salt Lake City indie and everything else. "indie" isn't a global musical quality, it means different things in different places.
In most cases, though, and definitely for vienna indie, we actually didn't set out to make a genre for a city. Rather, we discovered a cluster of artists that our data indicate are related to each other more closely than they are to other artists, and then we had to figure out a label for that cluster. We have a lot of data about artists, so usually (as with "vienna indie"), there's an obvious label that emerges from how a given set of artists are collectively discussed and written about and categorized online.
But sometimes there isn't. Or, more often, there is, but it's the same terminology used for some other cluster. That is, we have two distinct clusters of artists in the data, but both sets are mainly described out in the world as, for example "tech house". So when this happens, we try to do some deeper research, and see if there's a subtle distinction we can ascertain. Maybe one group is mostly Scandinavian, or slightly more disco-derived. But sometimes we can't really find one. It's kind of just "tech house cluster 1" and "tech house cluster 2". So the way we've settled on naming those, as a last resort, is "more x", like "more tech house". The idea being: if you like tech house, but you've used up all the tech house in "tech house", "more tech house" has some more tech house for you.
Does that help?
As for sorting them, we don't currently expose any scores in the API with which to do this. But it's a good request. We have some internally, which you can see in the sorting and filtering options on http://everynoise.com/everynoise1d.cgi.
glenn