I aggree its more than likely a toe issue. You can probably go forever with a neg. 2.0 camber reading and not chew up tires. As for aligning the car the machines take there measurements off the rims so if the insides of the tires are worn to the point the steel is showing but they all have close to the same amount of depth left the car can still be accurately aligned. Thats just a way to get you to buy tires.