Bits of rubber don't come off from an alignment, you're likely scraping tire on something. I've had as much negative camber in the rear and -3.5 in front and nothing on my tire falls off. You will only experience increased wear on the outer edge and subpar handling from positive camber in front. Something else is wrong if tire parts are flying.
You can buy extended range adjusters for the rear which will help.
https://www.phastekperformance.com/2...mber-87430.htm
The front can have the holes slotted slightly but your car is just slammed. Camber plates just replace the top piece of the strut to tower and are a 20 minute install if you know what you're doing. They can help with camber but not toe. The guy shouldn't have an issue with toe up front even though he did.