They are Hankook Dynapro AS tires that were put on the vehicle when I bought it in March '10. I've put about 13k miles on them and had them rotated about 5k miles ago. I did not do the tread measurements myself, but the last time I had the oil changed they gave me all the tread measurements, and they looked pretty good. Yeah, I'm trusting someone else's measurements, but those people are ALWAYS trying to sell you a tire if they can, and they didn't even try after seeing my treads.
If it is the tires, then I think more people would be having this issue because there are plenty of people that don't change tires until they blow up, or are near bald. Also, most people don't rotate tires as often as they should. Now that the edge has been on the market for several years, there has to be a few thousand of them with sub-optimal tread wear running around. Of course I can be wrong, but it just seems like a stretch that the tires, that although are not the best brand, would cause such a potentially catastrophic loss of handling in an AWD vehicle of any type.
I agree with ThinLine, unfortunately. Whatever the problem is, they aren't going to acknowledge it, much less try to fix it under warranty.
Much thanks for all the good input so far, too. I appreciate the help trying to narrow this down.