I finally found programs that'll do what I've been looking for.
CloneMaster looks for exact duplicate files. Roughly 10% of my files were duplicates, scattered across the drive - mostly mp3s that ended up in multiple genre-specific folders as a result of a series of synchronization accidents, lol. Uses a ton of system resources, virtual memory, takes a long time, and is very slow, but performs as advertised, :D
FileRenamer changes the file names in batches. Say you ripped songs from a cd and are putting them into a genre-labeled folder. Unfortunately, they have the track numbers at the beginning. Ever tried to remove the first four characters of multiple files? Pain in the ass. I used this program to remove such numbers from over four hundred files. Took about thirty seconds. :)
I hope you find them as useful as I did! ^_^