After the issuance of a certificate of authority, the commissioner shall have authority to issue orders or to publish regulations that may be necessary for the proper enforcement of this chapter, and as the commissioner deems are in the public interest. The published regulations of the commissioner will have the effect of statute, and shall include in particular powers of regulating the form of subscription contracts and required and prohibited provisions in the contracts, and all other matters needing further definition or clarification and coming within the requirements of this chapter. The commissioner has the authority to regulate rates as required by statute now in force or hereinafter adopted by the general assembly, as provided for by the regulation of casualty rates or as approved by the commissioner by proper legal regulation.