1. Under chapter 17A, the commissioner may from time to time make, amend, and rescind such rules, forms, and orders as are necessary or appropriate for the protection of purchasers and the public and to administer the provisions of this chapter, its implementing rules, and orders issued under this chapter.
2. A rule, form, or order shall not be made, amended, or rescinded unless the commissioner finds that the action is necessary or appropriate in the public interest or for the protection of purchasers and consistent with the purposes fairly intended by the policies and provisions of this chapter, its implementing rules, and orders issued under this chapter.
3. A provision of this chapter imposing any liability does not apply to any act done or omitted in good faith in conformity with any rule, form, or order of the commissioner, notwithstanding that the rule, form, or order may later be amended or rescinded or be determined by judicial or other authority to be invalid for any reason.