How long roughly does a full episode take to complete...
Probably far longer than an episode of West Wing. The production values for 24 are very high and many of the actors are working on other projects.
That aside, doing this, which explains the random storylines and character disappearances
It's 24... random storylines are not rare.
And you said they were changing what they had planned, that means totally redone episodes, not small changes.
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