Well if you thought M3 was badly designed (which in my opinion is anything but badly designed). M2 is goddamn hell. Not only it has been badly designed and kept patched badly but it also has a very weird shader system. Not only that, but you'll relly a lot on external files like db2 (wow database files) and skin files. Also the reverse engineering is incomplete, particle emitters are based on mdx's particle emitters but are very patched and have a kind of weird mix. Also visibility on them, is unpredictable. I have reasons to believe either they have flags that turn them on on certain animations or their visibility is set in the databses. Here's the best format reference: M2 Format
Anyways, I'll send you some samples once I get home tonight.
Btw, I reversed Enginered the M3 Ribbon Splines (added versioning to Ribbon Emitters), the Shadow Boxes, The Forces, The IK Joint Behaviors (kinda, need to find out something on them and figure how they connect to bones), The Rigid Bodies and on my way on figuring the Convex Hull part of M3 Physics Shapes (found vertices and faces, but there is a weird vector4 array which i don't know). I'll also send you that as well.