You're gonna need moderation, it is absolutely necessary when putting any number of strangers together in an online setting. Unspoken rule type deals are unsustainable.
Also, I would seperate based on age, preferably no minors. I've been in online spaces before where the inclusion of minors created tension and frustration with both the adults and the children.
These two groups are best left seperated, especially if you desire a system of "unspoken rules". It's a recipe for disaster.