A strong spotlight shines these days on the state Public Utilities Commission as it gets set to rule on how much the state's biggest utilities will have to pay for their sometimes fatal blunders and how much consumers will be soaked for the negligence of utility executives. As much as $8 billion over the next decade rides on decisions of the five-member commission, about to rule on the 2010 PG&E gas pipeline explosion that killed eight and destroyed dozens of homes in San Bruno and on the Southern California Edison decisions that caused the premature shutdown of the San Onofre Nuclear Generating Station.