Were you out there today??? Just got back from Pocono with PDA.
Anyway Adam (AZP and TeamIAC) went for a very long time on the STi totally stock (except maybe for flushing the brakes) and he is a NASA HPDE and PDA driving school instructor. So no I wouldn't say there is anything you have to do except print out PDA's tech form and get it completed. I would however strongly encourage you to flush the brakes.
For myself, all I did for my first STi track event was change the oil, flush the brakes and put on DS2500 brake pads. But Adam ran the OEM pads on tracks and auto-x till they were near gone.
Ed.