The most important piece of your track setup is the tires. Even a perfect chassis setup can feel like junk if you do not have the proper tires under it. I would check with others at the track to find out what works best before fighting with smaller adjustments. You mentioned that your fronts are a bit worn, how about the rears? There are several tread patters that work pretty well on many conditions.

The ride height adjustment should be made from where the vehicle settles on its own after dropping the vehicle from several inches of the ground. You also need to take the measurement with the vehicle ready to go run. A measurement with out the battery would not be very useful!

Also, the heavy center diff fluid is good for our brushless setups for better efficiency, but it is not necessarily the best for chassis setup. The heavier center diff will prevent dumping power to the front diff and keep a closer balance front to rear. However, this has made the rear of my car a bit nervous at the same time. With a normal center diff setup, there is less power going to the rear, and less chance of breaking the rear tires loose. If you can keep control of the car, you will probably accelerate harder, but it will take some more effort to keep the rear from coming out under acceleration.

Bryan