Sorry I never responded to this post. You cannot achieve what you are asking for - you can't just delete files from Google Drive and then sync to the folder. The reason is that there is a database stored in the cloud folder, and that database still has a reference to the song tied to that file. So it will still try to sync that song even if the file is missing. I recognize that you are wanting more of a file-based sync, but that's not how the feature is implemented. In order to be able to synchronize all of the rest of the data properly, the two databases are synchronized, and files are created/deleted based on what is in those databases. So you need to do the deletion in your library on the tablet and sync that to the folder.
Mike
Mike