The commissioner may, by regulation, exempt in whole or in part any company or class of companies, and any officer, director or beneficial owner of securities of any company, from the provisions of sections 38a-117 to 38a-123, inclusive, upon such terms and conditions and for such period as he deems necessary or appropriate, if he finds, by reason of the number of public investors, amount of trading interest in the securities, the nature and extent of the activities of the company, or otherwise, that such action is not inconsistent with the public interest or the protection of investors. The commissioner may classify companies and prescribe requirements appropriate for each such class. No provision of sections 38a-118, 38a-119 and 38a-120 imposing any liability shall apply to any act done or omitted in good faith in conformity with any regulation of the commissioner, notwithstanding that such regulation may, after such act or omission, be amended or rescinded or determined by judicial or other authority to be invalid for any reason.