I'm thinking something between a forum and a bug tracker, with UX like StackExchange
TL;DR:
a) Quora has superior search and multi-layer taxonomy (see Quora Topics)
b) Quora allows others to suggest edits on content -- crowdsourced proofreading and updating!
c) Quora allows users to create content for you -- crowdsourced documentation (coincidently building a hiring pipeline)!
d) Airbnb's mission/business is to help people list and book places to stay, Airbnb's mission/business is not to engineer a great help center or build a collection of all the questions and answers people might ask about Airbnb. Focus on what you're passionate about -- hosting cool places to stay.
e) Quora's mission is to be "a continually improving collection of questions and answers created, edited, and organized by everyone who uses it." [1] In essence, it's Quora's mission to organize exactly this type of information...why not use it for what it's trying to be?
The message board is great, probably that's the most important channel for feedback. But there's also email and social. I'd like to integrate them