I just joined the Ecobalance list today. I've participated in communities that fell apart over the sort of things you're discussing. It's good to see people trying to hash these things out, but dissappointing that the same things are still coming up that bedeviled us in the '60s. I've lost friends to nasty belief systems, spurring me on to study why people do what they do. The concept that I'd like to introduce is Memetics, the idea that ideas and groups of ideas can act like infecting viruses.
People then act according to the urges of their memes, rather than rational consideration.
I look forward to participating with you all.