My EGR is disabled anyway.
Regarding the O2 sensor, someone show me that reading both banks will really make a difference. Like I said before, if one cylinder is running rich or lean (which is the only reason you would really want to read every cylinder) in relation to the others, the PCM isn't going to be able to tell anyway. If it does notice something, it will only make small adjustments because all the exhaust gases are mixed. The PCM isn't programmed to think about it any other way than global adjustments across all cylinders (except skewing which is a preset anyway). It would go like this...
One cylinder starts going real lean say due to a bad injector. The PCM notices a slight drop in the O2 mV levels and slightly increases the PW to compensate. The slight adjustment isn't enough to make a difference on the one cylinder, yet it's now seeing the right numbers because all of the others are slightly rich. You still have the same problem.
What kind of hard data would you want to see to satisfy your doubt? I can't think of any tests anyone can do without a full engineering lab of equipment just for this purpose. I have no problem with where it is as the fact that it samples all cylinders as one keeps it form doing anything helpful if something did change from one side to the other.
