I think this might also stress the importance of backups. I know how you feel because I've done stuff like this too, and it really sucks. But what if your hard drive had simply failed? I think if I attempted something like this I would have run a test on a smaller data set that was quarantined somewhere, maybe on a different disk partition if needed. Most of the scripts I make are cheesy utility scripts, but as soon as they start changing any data I become rather paranoid. Of course I say that now, but I'm sure sometime in the future I'll blow up my computer anyway....
Well I guess hindsight is 20/20, but maybe a better solution would be to move anything not on your list to a specific directory that you manually sort through. It might be a pain, but a bit more safe.