1. You can A/B test individuals, but it’s nearly impossible to A/B test communities because they work based on a mutually reinforcing self-conception. Use a combination of intuition (which comes from experience), talking to other community managers and 1:1 contact with a sample of your community. But you’ll still be wrong a lot.
2. Public forums are not a useful way to get feedback, but are a useful way to get buy in from the community. This is true of both online and offline communities.
3. Communities are unpredictable. Don’t take the community’s criticism too personally or you’ll become afraid of change and slow. Instead, be open, thoughtful and move quickly.