I think the right rules could help a lot.
Can you point to any RPG running on the web that has actually achieved all of that? If one exists, I'd be interested to study what they did. I did make 1 or 2 forays into "large" web RPGs like you describe, back in the day. I found the administrators to be exceedingly immature and the writing quality low. The admins were inclined to get bent out of shape about small aspects of the game fiction, and their customer service ethic was extremely poor for how they handled differences of opinion and approach. I really have my doubts that any large organization would do a quality job of this, unless they were paying some people to do it, and firing those people when their management proved substandard. I don't think the typical large group of internet volunteers can handle it, and I say that as a veteran of many open source projects as well, thinking back to all sorts of tiffs and dramas about "how to do things."
I got focused on what I could actually handle, about 5..7 people with no more than 3 independent units of action. I consider those games successful, for my purposes back then. Unfortunately most, possibly all, of my email archives of those games got wiped out in some Windows catastrophes over the years. So I can't exactly show you what I did... and I don't really have time right now to do it again, tempting as it might be.