What kind of "mileage" do you get with your slicks?

It really depends on your burnout style...as in how much you need for your car to hook with the size you're using?

Most of the 9/10inch tires I've been around on 12ish second bracket cars had the wear dots pretty thin around, give or take, 150 runs.

I think you've done ok, considering. As long as you have enough tire and they work, just spin to clean & slightly heat. Smoke shows get expensive over time if you don't need it. :D