Triple Post:
So after some hacking with me and Kirby, we have found out that there is a file within the .nds file that stores the location within a .rg file for each act (bosses included). It seems that the latter half of the file has X/Y locations of the rings. I haven't learned much of it, perhaps Kirby can elaborate a little after this.
But yeah.
Tl;dr: One step closer to Full maps, and Possibly a Level Editor.