Player keys for doors and chests would be a really cool concept imo.
Have each door with the option to take a key mould for just that door or chest(door radial menu?)
The owner and clan mates can access like normal but if they have an ally or a trade partner they can give them a key to say the front gate to get in or if you have a trade house with player specific boxes to leave your trade in then you can give them a key for access to that.
And with the mould would be fun opportunities like stealing a mold from someone to forge a key
What do you guys think? Just a random idea i had