When figuring the GOO score minus the terror track, do we add both GOO (Shub and Ithaqua) values together on scenario 5? I've never figured scores for a multiple GOO scenario and was wondering if that was the protocol.

Good question, but I'd say the scoring is 12 minus terror since 12 is the number needed to trigger the AO.

Update: Looks like JR just confirmed this in the FAQ.