Yes the white PVC is the AC condensate drain. It comes from inside the house via a electric pump and then is drained on the other side of the sidewalk into a 3' x 3' x 3' gravel filled pit. That is the current code in California.
The sub-panel is what I heard from others as well. Basically, strip out the main service panel of all breakers and install new 200 amp breaker in MSP to feed a new subpanel that sits between the gateway and the main panel.