I ride a mix of city and hwy. and have a gravel driveway. I'm equally surprised that people get so little mileage on their tires. I'll probably get close to 20,000 on my stock Bridgestone tires (16K now).
I have never had any wobbling problem. I wonder what the effect of tire pressure has on wear, etc. I've kept 32/36 in my stock tires since new and check it regularly.