That isn't the problem, you may move it wherever you want, but it MUST be moved from within the Unity Editor. Otherwise Unity will assign new GUIDs to these objects and they will be treat as new objects.
In any case, if you want to fix this, you can actually do it - its not that complicated. Basically you turn on "Debug mode in the Inspector", then select your sprite collection data objects. The "Script" reference should be null there. Drag the tk2dSpriteCollectionData script into the slot to reconnect everything. Make sure all the sprite collection data / etc objects are all set up correctly, and then make sure other script references for animations, etc are correct (based on the error you were getting, I think they will be fine).
Ideally keep the GUIDs to match the original ones in 2D toolkit, so there wont be any problems when updating in the future.