Rob,
Regarding the SVX "unknown high cooling system pressure.", may I ask if you've had the radiator cap replaced and had a Subaru tech drain/refill the system? (If yes, please ignore the rest).

The reason I ask is that I thought I had cooling problems on my old Forester which turned out to be a worn out cap and then air left in the system (which led to erratic temperature spikes). Subaru cooling systems require a special tool to top off once you've opened the primary radiator cap.

I thought I was losing a head gasket, but it was just a bad cap and the resulting air in the system (which got there when the overflow tank went dry).

-Zeke