Yeh, good points Krispy.
Adding to your explanation of the smoke, I was also wondering about this facility for creating rain in the stadium, or more precisely, what might be in this rain? They have said they can create rain if nature doesn't oblige...bit of an odd statement. They need it to rain? Don't know if they've used this already? I didn't see the entire ceremony err ritual.
If they used this facility at the end of the games to distribute viruses to many world leaders / athletes with a delayed incubation period, I guess that could be another facet to add to those you've already outlined.