Your approach to developing communities should be deeply rooted in psychology. So why aren’t you very good at psychology?
Why haven’t you used theory to identify the specific motivations for members joining your community? What is the motivational lever (belonging, recognition, power etc…) you’re going to pull to get members to join your community?
Finally, there is a wealth of information on resolving conflicts and reducing aggression. Use it when trying to fix personal issues in your community.
You will never know for certain how people will respond to our actions. But you should have a defensible idea. It’s all available, for free. Start with Wikipedia, buy some books and become very good at psychology.