This *might* work.
Load ftpiiu_everywhere, copy everything from /slccmpt01 to a local folder.
Run ShowMiiWads and point it at that folder you just created. From there you should be able to install / remove titles, and then wipe /slccmpt01 and rewrite the new virtual nand over ftp.
* Edit...
It's not the movies or games downloads that I would worry about, like breaking into networks, downloading encrypted things, spying on network traffic. I have seen so many "Top Secret" seals on files when I was a kid
I was obsessed with finding UFOs, a surprising amount of US files where stashed on computers in other countries, China back in the early 90s omg sooo much