Guys, a restaurant has 3 states
First, State is a NPC restaurant which has full staff and full behaviors of a restaurant. I like to call NPC state.
Second State is called Player controlled State, but broken, this state as a NPC restaurant will try to run it as a NPC State restaurant except it will simulate the area that is broken, however the house hold will receive the money instead of the unlimited npc bank. I call this the broken state.
The last one is a Full player state, this one runs the restaurant with all required sims working at the restaurant, until something happens to the restaurant, to make it break.
The causes of the break of restaurants is sim in the restaurant became playable by player actions, second npc sim death and restaurant can't function for player restaurants even when not controlling that house your get a notification.
Game will allow players of other houses to marry the restaurant employees, but won't allow it in households that own the restaurant if the resulting action would break the restaurant.
A good example Sim 1 outside household marries hostess employee since that sim don't work for the owned household marriage is allowed, restaurant breaks, when said sim moves in with each other.
Example 2 Sim household owns restaurant, their young adult sim 1 marries waiter #1, if restaurant don't have additional waiter slot unchecked waiter, marriage won't be allowed, because it breaks the restaurant, however marriage will be allowed if the marriage don't break the restaurant, but it has to be done from outside the restaurant lot.
I hope this helps.
