All, just following up. Took my LC back into the shop and tried to give a good description of what I had been experiencing (and mentioned some of the tips y'all pointed out -- like driveshaft greasing etc.). They said they looked at everything they could think of, and nothing stood out as being messed up with the calipers, but the front rotors were warped.
First 2 sets they gave me were Duralast Gold, the last set that warped were Akebonos. They're ordering OEM from Toyota and putting them on tomorrow. They're submitting the akebono set for warranty, so not sure how much they're going to charge me out the door for this ordeal.
I guess I'll give another update in 5-10k miles to see if the problem is solved. I'll definitely work on my braking habits to try and avoid build-up during stops.