Mr. Fordahl knows what he is doing. Smart guy, he is. I agree with getting some track time to get used to it at the limit in a safe environment.
Stock, cars are designed to understeer even while braking, you already know this. Sounds like your car is now nearly balanced and it just requires a different driving technique.
The turn described sounds like the one from the UW to 520 eastbound. A wet. tight, dropping, blind, decreasing radius right, often with stopped traffic somewhere not visible at the entrance. Yeah, that could be interesting entering hot and not knowing where (if) there is stopped traffic.
Please take care of yourself and others and attend an autocross school and get some track time. I didn't and destroyed 2 perfectly good vehicles, luckily nobody was hurt.