Wow the KW kit is not a bad option really if you look at the whole package as 4 factory dampers would run about 2-3k anyways and it comes with coils too! What settings do you run on yours? Are they really plug and play? Just curious.Absolutely understand having the ride height for a daily. My car is a daily too and I have 4 inches of ground clearance and I love it! No more smashing the front of my car and driveway ramps and stuff like when I had it lowered. That’s why I really like my KW DDCPNP coilovers you can lower the car a bit and still have a great daily drive ride in natural mode and an amazing track ride in Dynamic or Race mode. They are expensive but they improve the ride in all modes really amazing!
Stock springs are OK but the car has so much power at porpoises on acceleration and then comes slamming down when you brake really hard. This is tough on the brakes and tires. You can manage it by trying to drive smoothly and no hard acceleration or hard brakes it just slows down your lap times though.
Yes you should change the differential fluid about once every 15-20 track days depending on how hard you track.
those micro cracks you see are totally normal. You need to inspect your brakes though all the time and make sure that none of the cracks go to the edge of the rotor or if they’re big and wide enough to hang fingernail on. I’ve gone through about four sets of rings now and only one says it got to the edge but the rings were pretty much worn out by then anyway. Girodisc brakes are so good, GT3 level good! But unless you track a lot the OEM iron rotors are fine just put better pads on of course and better brake fluid. Also changing the brake hoses to stainless steel hoses is a good thing to do if track a lot. Be sure and change the brake fluid often especially if you get the brakes really hot.
Yes, I'm running Ravenol 325+ brake fluid and for the 4 events I did at this year, I always bleed all 4 corners out prior to as I wanted to make sure fresh fluid is in the calipers. Safety first! I also run race pads, maybe not as aggressive as yours (EBC blues in rear and PowerStop track day pads in the front), but no issues stopping what so ever though.
I did some research on the cracks and I didn't know that condition was called heat checking. Learn something new every day!