Good and important questions. I find it interesting, and indicative of a broader tendency at LessWrong, that books are the first place you looked for an answer. The academic approach has its place, but if you're looking for advice you can actually put into practice, it would be more helpful to find some people who have successfully built communities and ask them what they did. Talking to a few thoughtful people who have built successful mid-size businesses, community organizations, or online forums from the ground up is going to be a lot more useful on the margin than thinking more about a public goods game.