on the Koni shocks, I am wondering, on the round metal plate that slides over teh shock and rests on the spring perch, where the spring sits in it... that plate, although it is circular, has a flat spot cut away along one edge. Is there a reason for this? Is that flat spot supposed to be oriented in any specific direction when installing it on the car?

yeah the flat spot is supposed to be facing the wheel to assist with clearance.