The point of the 100 hours of pre-aging is to get the set ready for a professional calibration. If you don't plan on having a professional calibration done, pre-aging is not required and just wastes energy.
Just set if for THX Cinema and start enjoying the set. Once you get familiar with the menus, dial in the C-net settings; I think they are little better. There is nothing wrong with watching a letter boxed movie. Just don't do it continuously day after day. Stretch or zoom 4:3 content if you watch a lot of it. Do make some effort to avoid prolonged bright white logos until you get past the new plasma paranoia phase of ownership. Some posts have indicated that some sets have a tendency for IR. Many others do not. Until you have had a chance to get familiar with the set there is nothing wrong with a little caution.
After a while you will realize the set is a tank and can take a lot more abuse than what you would think after reading this thread