HadEnough, I love your post. I have read hundreds of postings on forums over the years about tire pressure and the various opinions. Me? I take the manufacturer's recommendations and then adjust them a little but, like you, I also use my eyes and make sure the tread meets the ground in a parallel fashion. One big caveat: don't exceed the max psi on the tire and on my E tires that is always 80 psi cold, which will go up to 85 on a long drive on a really hot SW day.
To each his own. You can take a straight edge and put across the tread and see if it is relatively even. Don't attempt to do this going down the road. :) :)