* Do not allow questions on GitHub issues, it's a poor place for conversations. I find Discourse or some other forum (or mailing list) a better place to do that, which allows community participation (and you can automate moderation using something like https://github.com/pierotofy/issuewhiz)
* People owe you nothing, just as you owe them nothing; you don't have to fix an issue or merge a pull request because somebody opened one.
* Try review and merge contributions, but on your own timeframe. If people have urgency, kindly invite them to get a paid support agreement.
* Don't engage in quarrels; you always have the option to ignore or ban the offenders.
* Document FAQs.