The steering wheel "shake" thing:
When your tires wear unevenly this can cause the steering wheel to shake at higher speeds. What exactly caused your tires to wear unevenly is the real question, and may have already been addressed in Hyunai's technical service bulliten # 06-50-13, available for viewing on the HMAservice.com site.
I had the steering wheel shake problem myself with my stock wheels and tires, at about 10,000 miles, but now that I've switched to aftermarket wheels and tires I think this may have solved the problem...I won't know for sure for a few thousand miles yet (after the new tires show some wear).
It could be an alignment problem causing this, but it is more likely a "wheel balance" or "wheel/tire out of round" problem, as addressed in the Hyundai TSB. The new Accents only have one adjustment possible to align the frontend, the toe setting. Camber and Caster angles are built into the frontend parts at the factory, and if one of those angles are off, it means that something is bent. This suggests that an alignment-related problem is unlikely.
You could take the car to the dealer, and maybe the dealer will simply balance the wheel/s, and that will fix the problem....maybe. But maybe the dealer don't make much on something as simple as wheel-balancing, so maybe they will look for some better-paying answer to the problem. Impossible to say. You could also pull the front wheels, and take them to an independent garage to have them check their state of balance.
Unfortunately, whatever the cause, once the tires are worn unevenly, unless you have evenly worn rear tires to rotate to the front of the car, you'll need to replace the unevenly worn old tires with brand new ones, since the unevenly worn old tires are going to continue to make the steering wheel shake even after the initial cause of the uneven tire-wear is remedied.
With the perfectly balanced new tires and aftermarket wheels now on my Accent, there is absolutely no hint of steering wheel shake, thus far. After a few thousand miles I'll pull these wheels off of the front to get a good look to see if the driver's-side tire is again wearing irregularly, as the stock one did. If it is now wearing evenly I have to think it was definately a "wheel balance" problem. However, if the NEW tire is wearing unevenly then that would lead me to conclude that it is definately not a "wheel balance" problem.