Hi,
first, sharing playmaker content should be done by exporting your assets using the "Export package" option from the assets menu.
WARNING: Always remove the playmaker.dll file in the list of assets you are going to package ( Unity will give you that list before you save it). Playmaker.dll is not permitted for distribution.
Second, Unity Prefab system do not store reference to objects in your scene, only reference of gameObject parented to itself. You will have to manually set these scene gameObject references after the prefab is instantiated. USe of global variables is commong in this case, but you can also simply send an event to the newly instantitate prefab right after you created it and pass it a reference to the target you want it to follow, or have the prefav itself find out from your system what it needs to follow ( maybe find the player by tag, or something)
bye,
Jean