Too much rear brake. That is how my car felt before I put the prop valve in. Scary thing is that I got use to that feeling for almost 2 years but def isn't the way to be driving the car. Hopefully this year when I have the Z back together and back on the track I can play with different setups. Also I am running a slightly harder pad on my front brakes.
As far as rear toe, maybe look at TTT rear control arms. I can let you know what my alignment settings are.
Questions for the true racers: if you are running much wider tires, you wouldn't need as much front and rear toe as someone running wheels lets say 3-4 inches smaller?