Yeah, been a long time since I've looked at Race Tech fork spring recommendations, but I remember them being at least 3 or 4 steps too stiff for anything but pro level Supercross, lol.
Also been a long time since I've had a KDX, but IMO a 0.42kg/mm spring rate is probably in the ball park for your weight, though Race Tech probably recommends a 0.48 or so.
Never had an '02, but stock KDX fork springs are very soft, so even a 0.40 would be a huge improvement.
A higher oil level really improves bottoming resistance and stiffens up the fork for the last part of the travel, and 100mm from the top with the forks compressed and springs out should be in the ball park.
Kawasaki usually jets the KDX very rich, so leaning out your main, pilot and needle will liven up the motor.
Coming off the big KLR, I think you will really enjoy the KDX on the single track once you get it dialed in.