TL;DR: Games made in the weapons/vehicle creator to be placed into the world for added cosmetics and to relieve just the average passive boredom.
Ok, now I understand the game has a huge emphasis on creating custom weapons, custom vehicles, and the characters have a decent amount to it, but what about custom items to be placed into the world using the same creator used with weapons and vehicles? I think it could be done with how the engine appears. Simply take the same designer tool, remove requirements for specific parts making it a sort or cosmetic only type deal. It would allow users to make custom decorations, statues even for their forts or homes. I sometimes find myself making random stuff in the weapon creator without actually making a weapon and this just came to me.
-Less development need for things like chairs, fences(possibly), and other miscellaneous items
-A better looking, if not silly or serious, environment for the creative player
-Enormous quantities of added hours of gameplay on top of the large amount already there
The items could either be placed as physics items, like a ball that bounces around, or the bed that doesn't like to stay still when you touch it. Or static, like a fence, or a custom, cosmetic-only plant.