I bought an R1 AW X-Traction Camaro to run in some local club racing. I've read about the front axle slop, and sure enough, this car's chassis has it. My question is...how much of a problem is it? The wheels don't rub the body, and we don't use guardrails in club racing so the front of the body isn't going to hit anything. If I tighten this up, will I see a real improvement in performance?

As long as the tires don't rub the body, it should be ok. The extra slop does allow the nose to get lower, which makes for better handling.

Out of curiosity, I replaced the front axle, wheels, and tires with original Aurora parts. The front end dropped enough to cause the middle of the chassis to drag the track.

Try some front tires with a larger OD.

I've noticed that the earlier chassis are also thicker under the rear magnet than later releases. This negatively affects how much these earlier chassis can be dropped. I'll probably use these cars for parts since sanding, etc. isn't legal under class rules. The R3 chassis I have is about the same thickness under the rear magnet as the original Aurora stuff I have, and is much better in this regard.