Having managed to install beets with a very basic config.YAML file I would be very interested in seeing the code in your config file to see exactly which plugins you are using and how your are sorting files.
It is easy to find complex naming schemes for MusicBrainz Picard as there are threads like the one at Repository for neat file name string patterns and tagger script snippets but finding examples of how people are doing it in beets is much more difficult. I would like to see a similar thread for beets but I’m not sure exactly where such a thread should go.