I thought this story was very well done. Using a fairly subtle and novel monster to express a real-life situation. I think most longtime SF fans can relate to some level of the isolation, as many of us didn't really fit in with the social groups (that's why SF conventions are such an awesome thing). It was never entirely clear that the snake existed, but I could see it going either way. In any case, it doesn't matter because the metaphor is apt.
The leader was quite an interesting character too in that he had so much good and so much evil in him. As we all do, but both were alternately near the surface. All people wear different masks at different times, different aspects of their personality coming to the forefront. I suspect that his charitable aspect was truly and deeply scared and ashamed of his temperful violent aspect, but was also scared of the consequences if he would try to deal with that other aspect in a way that's less harmful to others. So he tried his hardest to be as charitable as he could to make up for it. The violent aspect was just as pleased by this course of action, since the charity provided it the opportunity for its evil.