a general question about these slots; is it possible to plug accompanying cords into a wrong slot on the Seasonic? or are they dummy proof? do the different labelled slots have different power outputs or are they all the same?
Dummy proof. Look at the connectors, they have some mixed square and rounded plugs. Those are there to prevent you from plugging it into a place that doesn't provide the right power on the right pins. If it fits into the slot, it works.