iCloud is threatening to delete all my iTunes files if I disconnect.

My iTunes library has nearly 15,000 files. Together with music, I have lots of audio files in iTunes. They are mainly lectures and foreign language lessons. I've been making them into Playlists and I sync them onto my iPod and also onto my iPhone. But when I put my entire iTunes library on suffle for a party, I'd get a lesson in the middle of it. I solved the problem by converting all my "non-music" files into "BOOKS." That solved the music shuffle problem and I still could put sections of those courses as Playlists to listen to in the Gym, on my walks, or while driving. So far so good.

But now that I joined the iCloud world, the system won't let me have playlists with "non-music" files. When I realized that the benefits of having iCloud are not as important to me as the ability to have music and "non-music" Playlists, I decided to turn off iCloud. But I haven't done it yet because I'm getting ominous messages that before disconnecting iCould, it will delete my files in all my devices.

Does anybody know how to get rid of iCloud without destroying my iTunes files?