1. You already figured this out I guess, but you definitely want to keep the resolution at 1920x1080. IMHO messing with scaling settings in CCC is just asking for trouble and probably to blame for the bad text. I got my PC to look awesome via HDMI to my 55LH40 by hitting the Aspect button on the remote until it was Just Scan.
2. Already figured this out too? I turned off the eco-friendly auto-dimming as it was too damn hard to see at night. No reason I should have to have my room lights on just so that my TV is bright. Electricity is cheap in ND.
3. Lip sync problems will only show up on HDMI. If you have a gaming console, set it up to send Dolby Digital (System menu on my Xbox 360). Then load up Guitar Hero or Rockband. Rockband will also have a setting in the game to turn on DD also, as it ignores the system setting. Try to play a song and notice how much you suck now. During an easy part close your eyes and try and play along with the audio; you will miss all the notes. The problem will still be there if you turn off DD, just not as bad. Using the calibration feature of the game you can get an estimate of the amount of audio lag. Mine is ~160ms with DD and ~70ms with just stereo audio (to be clear, that is stereo audio still over HDMI).
If you have a game like Halo 3, you can hear that the guns are shooting after you pull the trigger (DD on), especially with the battle rifle. When I got my receiver it was awesome how fast the guns were! Sadly a TV with decent engineering done on the audio would not have this problem.
Also interesting is if your receiver will send out the audio on HDMI and still play it through the speakers, turn your TV and receiver to about the same volume. Then do something that produces short noises, for example navigating around in the Xbox 360 menus. You will hear a definite "echo" coming from the TV speakers after the sound has already played from the receiver speakers.
With no gaming system you could try just watching a movie. With DD on I can see the problem. With no DD it is more difficult to discern. I think I see it but I am not sure. I think it would be difficult to tell if I did not know it was really a problem.
Anyways, I get more pissed with this TV every time I have to call LG tech support to get another technician to visit.