A warning that might spoil a bit your adventure on the long run: Your published pages will be exploited somehow. SEO backlink abuse, phishing, etc. Offering free public hosting is what people with ill intent are looking for, and you can be sure that at some point they'll look at your solution
Thank you! It is realtime across devices/instances for the active user. Currently it doesn't support collaborative editing but it's always been on the back of our minds if there is enough interest. Aside from just doc syncing for multi-users, we'd need to make some changes in the doc structure/presentation to provide a clean UX around that (without making the UI to complex). That said, it's not off of the table :)
re: public pages. Thank you and definitely top of mind for us to monitor.
It is real-time editing! We leverage web-sockets to sync across multiple logged-in sessions. But as of today it does not support multiple users collaborating on the same document.