Capabilities of Multiplayer?

[Evanlet]

So I was just wondering how flexible the multiplayer system is. For example, how in depth can mods get in the future, will vehicles be a possible addition from modding? (If it's possible to tell now)

 

This is just because the idea of custom servers such as Life Roleplaying servers with jobs dawned on me. There are offices (for jobs), buildings, grocers (jobs/buying food), and hundreds of houses for players to live in, you can farm (could be a job, where you then sell your crops to grocers who sell those crops to other players), in the next update you can fish (fisherman job), etc... So what if a person wanted to create a Life RP multiplayer server rather than the traditional zombie survival server in the far future? What are the possibilities?