Having just checked it, it looks like the only things that he's done to make it incompatible are removing/renaming the neck and humanoid joints bodyparts/definitions. It looks like he deleted the NECK and HUMANOID_JOINT body definitions, and included those in other body parts, making them redundant. So you can go through and delete those from the body definitions in the creature_spellcrafts_x files and that takes care of the error log, although there are doubtless countless other things that don't show up. That'd take all of five minutes. open the file, hit ctrl+h, in the upper field enter :HUMANOID_JOINTS: and in the lower field enter only one ':', then hit "replace all." Do the same for :NECK: and that should cover it, and repeat that for the other five files.
Actually, I just noticed all those :NECK: entries are redundant anyway, as the creatures using them are using a body plan that already added a neck. Heh. I'll have to go through and fix that! No point having a creature with one head and two necks, although that doesn't seem to be the result in-game.
Seems like that's most of the compatibility, though. I don't really intend to do versions compatible with various other mods that change how vanilla files are set up or even remove them, not at the moment.