First of all it allows market based prices, and second, there was a thirty day period allowed for any protest to be raised. Obviously, no one complained, therefore, what's the point?
I am not an expert on these matters, but it is my guess that these waivers are fairly routine, and allow for quicker price changes in a volatile market. faster price changes can work either way for the consumer, depending on which way the market is moving.
You are correct. However, a waiver for a company in Enron's ilk absolutely could not operate without one and without the waiver would have been required by regulation to disclose facts about their fiscal situation that would have exposed them.