I have a slight feeling you're making it more complicated than it needs to be... Like, how are you in a building with security cameras AND illusions? Surely the illusions make it harder for the cameras to do their job. And surely, since you're in a building, the giant worms can't get close enough to affect anything. Plus, the number of banshees would be unchanged since 10 feet ago, as would the scry spell.
I have a slight feeling you're making it more complicated than it needs to be... Like, how are you in a building with security cameras AND illusions? Surely the illusions make it harder for the cameras to do their job. And surely, since you're in a building, the giant worms can't get close enough to affect anything. Plus, the number of banshees would be unchanged since 10 feet ago, as would the scry spell.