You don't use common5 at all; there's some other file (selcharactersomething.pac) that you use.
Is that the only modification? And do I rename it to anything?
That's about the extent of my knowledge on the matter, though if I had to guess I'd say you probably remove the language indicator (i.e. "_en") at the end.
This is excellent. Awesome stuff, Dragon. Maybe you should give it a blog post
Also, someone needs to steal the code and use it to make Ganondorf use a sword when he taunts (or just change the taunt to another button). Probably just need to tack a Generate Article to the end.
As for the TC's Victory Portrait issue: the files in the menu\common folder are the victory portraits. They're not included in common5. Just copy that "menu" folder to your SD card's "pf" folder and you're done.