Regarding your list of potential mods or not, I just picked up my care with the single adjust Penskes and those combined with the much superior Bridgestone tires completely transformed the car. Not only is it now point and shoot accurate with way less understeer, the "springyness" is gone and yet the ride is not at all harsh. I would say it is way more comfortable and less fatiguing than it was stock. (The Tires are fantastic).
I also have the short shifter and I feel that is a huge improvement as well.
Must my 2 cents