Hi sisunator!
Let me try to help you! Be sure to read through before starting so you can understand the procedure
In order to delete these annoying AUTO ratings you need to backup your songs that you have rated yourself first. The easiest way is to create playlists according to rating stars e.g. "One Star" for all the songs you have rated with one Star.
Now save all your playlists by exporting them to a save place (see picture below) (sorry for german/ i was too lazy to switch languages)
After this you can start to fix your library by simply deleting your library files from the following directory:
(Be also sure to save these files at save place just in case)
Macintosh HD/users/"username"/Music/iTunes Library.itl
Macintosh HD/users/"username"/Music/iTunes Library Extras.itdb
Macintosh HD/users/"username"/Music/iTunes Library Genius.itdb
Macintosh HD/users/"username"/Music/Album Artwork
This deletes all data iTunes has stored for you - You can now start with a brand new iTunes library! All Ratings and Play counts are reset to none.
Now we come to the part of restoring your files. Therefore simply add your all files with the CMD+"O" shortcut again. (Much easier if all your music is stored in one folder)
Then import your exported playlists by using "Import Playlists" in the same dialogue as in the screenshot above.
You will know have no ratings at all!
To restore your ratings take the "Star" playlists from above. Mark all songs from one playlists (CMD+"A") and change their rating to the one you had before.
Do this for all five playlists.
Et voila now only your ratings are back and you have no annoying album ratings anymore!😉