Well I can tell you for a fact your air pressures were way too high. I would try something around 32 psi in the front next time.
You are very close to having a perfectly balanced car. Perfect balance in steady state corners is very hard to master. I was going to actually recommend reducing negative camber in the rear as well. My guess is, mid-corner the weight transfer front to rear has stabalized therefor, you are basically having too much grip in the rear.
Like you mentioned though, loosening it up for one thing is going to effect the other parts of the corner. I would defintely recommend trying it to see though, it may not be as loose as you think.
Also, leave the toe-out.