S, So that will never happen if you keep your songs in the device only (no cloud), right? I ask that because I like to write the tags myself and have never used automated tagging. I don't want to use Microsoft's ID3 data!
I'm not sure if keeping it in the cloud will make a difference.
I too liked to do my own thing with my ID3 tags. I preferred to take a 2 disk set and renumber it as just one big album, also genres, I don't always agree with the pre-defined ones. But alas, once I decided to let MediaPlayer to go through all my music and update my music to match what MS has, everything has been fine. The only thing I do after MediaPlayer gets done, is I embed the album art into the MP3's.
Also, one more thing. If you reset your phone back to factory, take OUT your SD card with your music on it. Only after the reset is done, put the SD card back in. Start the Media app, then leave it alone for awhile (start button out, don't use the back button). This allows the app to catalogue your music. The length of time needed is dependent on how much stuff you have.
One more thing. If you have playlists on your PC, that you want to put on your WP... This just sucks. What I have found is to delete the songs off your WP that are in your playlist. Then use the WP Desktop App to put the playlist, and songs, onto your phone. If your don't delete the songs off your phone first, you WILL end up with duplicates or a mess.
For me, I have just a few playlists, with a minimal number of MP3's in them. Otherwise I just do a "deep shuffle" on all my songs from the start of the app.