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1. If we watch individual photons as they are going through the slit(s) they make patterns on the screen like they are particles. If we don't watch them, the patterns are those of a wave.

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If by "watch" you mean "entangle the photon with some system in such a way that information on the path is stored in that system", then yes.

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2. If we aren't watching, but we have a movie camera pointed at the slits, the pattern is of particles.

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Again, this is true as long as the state of the movie camera is being entangled with the state of the photon.

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3. If the movie camera has no film the pattern will be waves.

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I.E. if the state of the movie camera (and everything else in the room) does not become entangled with the photon, then we will see waves.

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4. IF THE CAMERA HAS FILM AND WE DON'T LOOK AT THE SCREEN UNTIL AFTER WE LOOK AT THE PICTURES, AND ON THE WAY TO THE DRUGSTORE WE FALL AND RUIN THE FILM, WE WILL SEE WAVES ON THE SCREEN. In other words the photons "know" that we will not be able to see them go through the slits, even though our inability to do that is because of an event in the future!

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If by "destroy the film" you mean that you disentangle the photon/screen state from everything else (including the camera film), then this is right.

This seems shocking at first, but these are all subtly the same phenomenon at work. If the photon/screen state is entangled with anything else, interference will not be observed. It doesn't matter if it was or will be entangled -- the only thing that matters as to what you will see right now is whether path-information is held by some other system via entanglemet right now.