i'm guessing that the god-alloy properties are mirrors of the base metals. For example, I would guess that Larasium alloys produce Mistings, Sazedium (which is how it should probably be spelled, considering that Leras and Ati used their full names) alloys produce ferrings when eaten. Maybe each Sazium alloy can store the corresponding Allomancy. i.e. "Harmonious Steel" stores the Allomantic power to push on metals.