As a side note, a user in
this forum seems to imply that (1) is indeed the choice I want. So, anyway, I just undid it by hand (it was really simple - I just copied back the fonts I deleted and uninstalled mcconvert. Some of my filenames seem to still be in English, strangely, but IME support returned, so I am happy. I figured there was no reason not to keep the unicode fonts.) Next is stubear's script. I spent a little bit of time trying to make a NAND backup, but the command doesn't seem to be in the dm-menu as it is on other models, so I will just have to not screw up. Thank you guys so much!
Edit: I ended up just changing the language setting to zw_TW since the site didn't want to load for me. If it annoys me, I can always run the script, but for now it seems fine; almost everything is in English, and what isn't so far seems like a couple file names in katakana. Again, thank you guys so much for answering my incredibly obvious question.