What are the criteria required for establishing a new Minyan?
Some considerations (not an exhaustive list) for why people might want a new Minyan:
Different נוסח (perhaps very few people in the community Davened this different נוסח at one time, but now more people with that נוסח have moved to the community).
Personal grievance (shared by the group).
Convenience (location and/or scheduling).
Not Heimishe enough (ie., no socialization, even at permitted times or after Davening).
Personal preference (speed, speeches, announcements, Mi SheBerachs, etc.).
Are there hard and fast requirements for establishing a new Minyan? Guidelines? If a Minyan is established not in accordance with the requirements/guidelines, does this preclude someone from attending the Minyan, whatever his motivations might be?

