Why does my characters explode when animated?

Have you checked you don't have any Segment Scale Compensate in your referenced fbx or in the joints of your source animation?

Golaem Crowd doesn't support this feature.

Here is a little script to deactivate it on all joints before exporting the fbx file for the Geometry Group:
$joints = `ls -type "joint"` ;
for( $joint in $joints )
    setAttr -e ($joint + ".segmentScaleCompensate") 0 ;