Cameras aren't related to stories.
Their placement is absolute.
If you need to change elevation within one continuous sequence, figure out how to climb a stair with them or something.
For separate sequences, make a new 'path" and control the visibility of each separate path using the camera dialog. ["Path" button]
As for speed, you've got to relate the number of frames between each camera placement with the playback speed. Assuming 30 frames per second [? somebody confirm ? ], calculate how many frames you need to get the required animation length. ["Path" button]
But whatever you do, Archicad makes bad fly-thrus because the camera cannot be smoothly accelerated nor each camera target smoothed.
Dwight Atkinson