Okay, a few ideas.
Fire system: If the server detects and kind of fire department job (also an idea) random fires can be caused on light sources (Another idea...), but are rare per tick.
Light sources: Bricks such as lamps, fireplaces, stoves (idea) etc.
Food cooking: Use stoves/ovens (buy-able items) to cook your food, and use a fridge to keep it from going raw in your inventory. (Idea)
Inventory: A small inventory system where you can carry a gun license, holstered guns, driver's license, house keys, etc.
Firefighter Job: A job including a hose to put out random fires caused by light sources, including a fire vehicle.
Mail: A mailbox can allow notes to be left in it/items for the owner who has a key.
I have tons more ideas, and may post a few soon.