Either I setup the same exact bone structure in blender as you by luck, or the placement doesn't matter. With your same pose rotations duplicated the cube moves exactly the same as yours. Does the position of the bones in the armature matter or is that overwritten by the center and position values in the pose_statue function?
Where does the count of 6 come from? I have 2 actual bones on the armature, and 8 vertices. I was able to add 2 more for 8 (just adding to count and center lines) adding more lines to bone_rotations as well but saw no effect. I'm guessing each line in bone_rotations is x,y,z for each bone. I did play with the values for positions, centers, and rotations but am having a hard time telling where each correlates to on the model.