Health insurance cooperatives, though they aren't prevalent, are a great compromise between the single payer system and the universal healthcare. I think that a health insurance cooperate can offer the flexibility of a single buyer system while maintaing the class and required regulations of a government run system, so in my opinion: yes.
Yes, health insurance cooperatives are a good compromise, because they allow people to work together to provide health care. People who participate in these cooperatives have a sense of ownership in their health care, and an interest in the other people who are participating. They might not be perfect, but they are a good compromise in the health care system.