I haven't had the shakes on either of my HHRs, and I've owned my 08 for a couple years and have put 20,000 miles on it.

Here's what I have done, but as always, YMMV:

Replace pads and rotors at the same time. Clean the hub surface with a wire brush to remove any contamination between hub and rotor.
Replaced front brake hoses
Replaced LCAs and struts
Replaced sway bar links and bushings
(Front end was very worn out on my 08)

Checked tie rod ends and steering coupler.

Torqued wheel lugs to 100 ft/lbs, in star pattern. IMO, this is very important. "Ugga Duggas" isn't accurate enough.

The issue with warping is that the discs are at minimum thickness right out of the box, no extra 'meat'. That's the design to save weight. My personal opinion is that any wear in the front end can contribute to shaking, and at first be blamed on the rotors but if unchecked may actually contribute to rotor warping.