"[F]or situations where the plan made the error and participants were not at fault.... [1] [E]stablish a look-back period of three years or the plan's statute of limitations, whichever is less ... [2] No interest should be charged on overpayments when participants are not at fault ... [3] Limit the amount of reduction for the overpayment to 10 percent of the new and reduced benefit amount ...[4] Prohibit demands for lump-sum repayments ... [5] No recoupment from beneficiaries ... [The DOL should] require that all plans offer hardship waivers and provide specific guidance concerning the standards applicable to hardship waivers ... Retirees facing a recoupment action should be accorded the full rights associated with benefits appeals."