As to meta-tags, no I don't have many. I rely on my naming-hierarchy to do the job, which it does. And I don't want to invest the additional time it would take to multi-tag almost 5000 tracks. Maybe someone has a way to shortcut this process?
If your folder structure contains most of the info you need, then you can use the Infer and Update Tags from Filename feature. Right click on some tracks and it's in the auto-tag by track menu. Definitely try it on an album or two at a time first, but then you should be able to do more once you know it's working.
There's also the auto-tag by album command, which can get info from the MusicBrainz database and I think Discogs if you have that plugin, one album at a time. It helps to have your basic title, artist and album tags as a starting point, although you can sometimes identify tracks based on the sound signature.
I concur with Zak. If you have at least minimal tags (title, artist, album, album artist, year) MusicBee can offer you a lot more flexibility in navigating your library than the folder structure. The column and thumbnail browsers, filters and auto-playlists, AZ jumpbar, etc all rely on tags. The jumpbar can do years if you sort by date rather than album or artist, and so on.
If you go crazy and start tagging multiple artists, for example, then you can do things like select Paul McCartney in the column browser and get all the Beatles tracks, and Wings, and tracks he's done under his own name. And if you've tagged composers you can do a search that will find all of the above plus tracks by other artists that he composed.
Most of us use tags to create the folder hierarchy rather than the other way around, too. As you add new music you can use MusicBee's File Organization features to do the same.