Blue Cross Blue Shield of Michigan has asked state lawmakers to give it more flexibility over the premiums it charges, reduce regulators' power to intervene, and toughen regulations for its rivals. If the not-for-profit insurer's controversial plan succeeds, the Michigan insurance market for individuals, which is one of the most affordable in the country, will be revamped. Blue Cross says the changes are necessary to curb the mounting losses that result from its status as the state's insurer of last resort.