I was wondering if you have vmd files of the animation.
Viewing post in Skeletal Mesh FBX Update comments
The Armature is the root of the model, Anima doesn't have a spine_04 or spine_05 and to add them would involve re-rigging, I should be able to fix the naming issues, I didn't make the rig with IK in mind, as you can usually add that in the game engine. I do not have vmd files for the the animations.