Re: Tire Wear
The Zeons are reviewed by many to have average-to-poor lifetime. Even with a 500 UTQG rating. And that would tell me that the tire compound is pretty darned hard (long-life).
An alignment by a competent Wheel/tire/suspension only shop may solve all of your problems. An import (Mercedes) specialist shop too.
I frankly (sorry, Frank) wouldn't trust my local dealer to do this.