First and foremost, this does not included any pvp aspects. Second of all, some may be disappointed that I'm not going to mention co-op in any way. So with that out of the way, here is my idea.
Kenshi's world is totally open ended. Random events occur, towns get raided, prisoners break out of slave camps and etcetera. So what if instead of pvp or co-op we take it in a different direction. Take for example people telling stories that they travel to a vault that's within the map. The first time they go there and there are a ton of slaves. Days, weeks or even months in-game time pass and they travel there again. This time however the slaves are all missing. But why? Did someone break them out? Did they escape during a raid from a different faction? Or how about a player also playing Kenshi ran in there, and was chased out by all the guards. The slaves took advantage of this and escaped then?
To put it simply, indirectly affecting someone else's world through the actions they've taken within theirs. Of course you can't have this happening all the time. So a simple randomizer code picks from one player's world, an action that was taken, and applies it to your world. You would have to limit the options the script would pick from. So player's that wipe out an entire city doesn't negatively impact your world and make it a barren place with no NPC's. But things like breaking out slaves, wiping out small camps (that can repopulate) and many other things could happen within your world.
This keeps the general gameplay flow consistent with what we have now. But whenever you discover these things you can always have in the back of your mind that some other unknown faction (player controlled) caused this event to take place. A random shop is broke because another player had robbed them dry the night before. A much more intuitive system that allows players to discover things and tell the tale later on. Did you go to the swamp and see a village getting over-run by blood spiders because another player unlocked the village gate?
The possibilities are endless. But we're still left with a world that retains the balance the devs had in mind. I'm no game programmer but because there is no pvp or co-op you could almost have one server to run the data being collected by players. A "simple" script that looks for tags being caused by players. And then pushes out a "simple" text file to a player's game to cause an event. I put simple in quotations because the only coding I know is website site stuff like php and mysql. So it would be like a person adding a thread on the forums and then people see this thread. But again, I'm no game programmer. This could actually be extremely complicated.
But think about it. Let's hear your thoughts! And everyone have a good one! We are almost to 1.0!!
Ofc, some backup function is needed. 
