Oh wow!
I just peeked in here out of curiosity, and I'm pleasantly surprised someone is actually making headway on SYM/FPS, since there are things I like about it more than Sol Trigger (probably the worldsetting and music mischief and maybe because Sol Trigger had a bit more of the BRS: The Game vibe that didn't appeal with me, if that makes any sense at all). I had peeked in the ISO sometime earlier last year, but quite honestly didn't find where the text was. I'm curious if it was compressed somehow (which you've probably mentioned regarding Sol Trigger somewhere here in this very thread, since they are apparently compiled in the same fashion)??
Wish I could help ya with the actual hacking/font aspect. I have 0 hacking capability, but in regards to the .ANM bit in your notes (which I was curious to read), SKL is a working format for 3D model skeletons, while .ANM, as you guessed, IS for the animation data the skeletons have to follow.
Sorry for the novella there, especially when I just wanted to say high five, it looks splendid so far!