Update!
A Chevrolet CSR contacted me yesterday and we together contacted my dealer's service department. We've tentatively set up an appointment for Thursday afternoon pending the availability of a loaner vehicle. The service fellow was able to find GM documentation of the ride height issue and the front sway bar end link nuts. A while later he called me back and said that he found an issue that GM engineers are investigating concerning excessive supercharger whine. He said it wasn't finalized into a TSB, but Chevrolet says it's safe to drive until they arrive at a fix. He also confirmed that he had ordered the springs and sway bar nuts and hopes that they arrive by Thursday.
I see that there's another thread recently describing a RPM-related whine from the engine compartment. I wonder if it's the same thing I'm hearing...?
So far, so good!
Tara