Seth - Rear camber and caster are not adjustable, so you're stuck with whatever the factory gave you. I would suggest going to 18mm on the swaybar just to be on the safe side for your first event. Then again, I've never driven The Egg so I don't know how tail-happy it is with whatever setting you're on now. If you decide that 18mm isn't enough it's not hard at all to change the setting at the track - hell, Ray and I did it on the Legacy at Las Vegas Motor Speedway, and that was with the car riding 1" lower than stock (so probably 2"+ lower than your OBS).
'97 Legacy 2.5GT sedan