Well, took the car back to the dealership yesterday. Service manager saw the wear, checked the records and said it is NOT unusual for tiers to wear like this on a 4 Matic! He tells all his customers not to go beyond 10,000 mile between tire rotations.
Not sure how much I can trust him, since I had to teach him how to read the tire pressure specs inside the fuel filler door. He wanted me to keep tire pressures at 33 psi, when it clearly states 35 to 36 on the chart.
He IS going to put the car back on the front end alignment equipment tomorrow and "tweak" the settings if possible. Once again, this car has the 18" AMG wheels/tires and sport package.
Sounds like Mercedes needs to learn a few things from GM!

 

Well, Just got back from the dealership. To their credit, they set up an early appointment and I was in and out in about an hour.
Bad news? They found nothing! Every single alignment parameter is spot on. Tire wear and outside edge feathering is normal and they suggest frequent tire rotations. Handling, such as it is, and "squirrelly" in crosswinds, well that's normal too. Part of the feeling is undoubtedly due to the very compliant body mounts, which ultimately make it ride more smoothly. Takes some getting used to.
I don't feel that Mercedes and I will have a very long relationship.