So basically you're going to ignore all (well, the vast majority) of the advice here and go with your gut? Well, I'm really glad we all bothered taking time to give you the benefit of our experience.
You've got vastly different compounds on the rear to the front, and as such totally different grip levels, and you're wondering why the car is doing weird things? I genuinely hope it is just a wheel speed sensor, but even if it is you've still got a mis-balanced car once it's replaced.