Here are some of my ideas:
A police/wanted system? x - You do a crime or something bad (Run somebody over, steal, ect.) either you could have multiple levels of a wanted thing, or a FoV thing so say if a guard happens to see you doing something he comes after you, and if he passes by others they follow. Or like the first, the first level a guard comes, then second level an upgraded guard, third level knights ect.
Have you seen this? It's the best real life thing I know of atm.
http://www.hiveworkshop.com/forums/...ersion-160282/?prev=search=hunger&d=list&r=20
A very good real life thing for jobs is when you get paid, tax is diverted from your pay (like today's life, because government is gay and takes your money) and then the government gives it to the poorest player. (again like todays real life).
Tax on everything in the game, so if something is 10 gold theres like 1 gold tax.
Making the player buy a license in order to have a weapon equipped (Carried Weapons Permit), and if a guard finds you w/out the permit you go to jail.
Also, prison, yeah. Fun.
I could go on forever with ideas right now, but I don't have the time to. I'll throw up more stuff later.
EDIT: One more thing, you could make vehicles require fuel to run. So say you have an item called Fuel/Mana/Gasoline or w/e you use in the vehicles inventory, so Fuel x1 would make the vehicle run for 2 minutes and such. That'd be a great way to make it more realistic.
More: Pets too, although I'd really consider this optional, you could have a variety of pets considering the large amount of animals in wc3. Guard dog, turtle, snake, ect.
And if you did add pets, you could have them require food also (hunger system above.)
Again, ton of ways to make it realistic, but I'll have to give more later.