Administrative Procedure; Specifies that issuance of guidance document or other statement interpreting statute without express statutory delegation to issue such guidance is an invalid exercise; requires statement of estimated regulatory costs for proposed or existing rules; requires retrospective cost-benefits analysis for specified rules after specified period; requires publication of materials used to produce estimates of regulatory costs in specified fashion; provides additional requirements for cost-benefit analyses; revises requirements for review of rules by JPAC; requires additional information to be published in FAC; provides for expiration of rules after specified period unless readopted; provides requirements for readoption process; providing exceptions to expiration & requires review of such exempt rules; provides for limited extension of expiration in certain circumstances; provides that party subject to enforcement action may challenge action on basis that agency lacked statutory authority for rule or guidance document; provides for challenges to rules for failure to comply with specified provisions.