Some films were recorded with a lower frame rate due to some reason. As for variable and standstill, I think this would only be needed when investigating a recording in detail. Not sure if they really need it. Perhaps they just want it to cover more use cases.

From what I gather, projecting preserves the viewing experience which is part of the film's value, not just the image. Plus, sound extraction and timing sync can be simpler with a projector. Scanners capture detail but might miss some nuances that make film unique.

[dead]