Charliehall-
you write (In fact, in a community with no true O shul, it might be a mitzvah to help out a halachic minyan in the basement of a C shul. Eventually they might get enough supporters to break away.) Actually R’Moshe has a teshuva saying exactly the opposite. He says if a orthodox minyan is looking for a place to daven they it is assur for them to rent a room in a conservative shul