the zune software piece is the one all controller of media on your zune device (30, 80, 8 or 4). as of now, you cannot remove/edit meta data or files on the zune itself, all of this must be done in the zune software.
to sync items, you basically can do it 3 ways:
- by file
- by playlist
- by folder
however, to remove or unsync/never sync w/the device, you have to go into each folder in the zune software and select all of the media files in your collection (not the device) and then right-click > never sync to remove the sync relationship for those files. this will in turn remove the files from your zune too.
also, if you have a playlist of music synced and remove an item from the playlist in your collection (not the zune device), it also in turn will remove the item from your zune's playlist and collection.
so hopefully that will give you a quick understanding of how basic syncing works. i hope Microsoft adds more functionality in regards to syncing like being able to see a full list of all of your synced items and also being able to remove synced folders vs having to go to each folder and then unsyncing them manually. smart playlists is also a must needed thing; i personally use them in Media Player a ton.
thats all for now.