Yes, if you move your iTunes folder from "Music" and put it on your desktop, I don't think iTunes will touch it.
All your media is in the "Music/iTunes/iTunes Media" folder. That is the folder you need to backup. It contains all your music, apps, podcasts, books, movies, TV, etc.
Once you've done that, you'll be good to go. I didn't backup my iTunes folder by the way and it's all still there...but be on the safe side.
Now.... That iTunes Library.itl is in your Music/iTunes/ directory. I deleted it and iTunes made a new one. The problem was the first few times I tried the method I found on these forums, I was getting errors. So, I deleted iTunes using AppZapper, then restarted my computer and used Pacifier to install it.
When using Pacifier, I clicked "Replace" for all the options. That seemed to do the trick and there were no errors.
When I uninstalled iTunes 11, it didn't touch the iTunes folder with all my media (Music/iTunes/iTunes Media). Why? I dunno...
I have everything backed up on external drives so I wasn't too concerned. All I ended up manually deleting was the
"Album Artwork" folder
iTunes Library Extras.itdb
iTunes Library Genius.itdb
iTunes Music Library.xml
So basically, after using AppZapper, and manually deleting those files/folders (keeping my iTunes Media folder), my machine was totally iTunes 11 free.
Then, I restarted the computer, opened Pacifier and dragged the iTunes 10.7.dmg file into it. I click the "Administrator privilages" so it would allow the computer to overwrite stuff and whatnot.
I clicked "Continue" and "Replace" until it was fully installed.
Then, I started iTunes, and it was all good.
When I first tried things, I got an error. I think the computer restart was needed to clear stuff out. I would suggest restarting before and after deleting iTunes 11. Then when you're sure your computer is iTunes free, use Pacifier to install it (with admin box checked).
That should do the trick.