I think it should be a once-off, because after a few times, it will get very tedious. But it is a good idea.
Something Unusual: This is how you will need to code the random events in:
1) Use a trigger (look
here for a tutorial on triggers) to make the event, and then use the jump_to_menu operation to go to whatever menu it will trigger.
2) Make a mission template for it. (ask zephilinox about mission templates)
3) Make consequences for the end of the event. (Inside the mission template)
Good luck! If you figure out how to exit a scene using a mission template, tell me, too!