I don't get the confusion over the start time and the script. Scott has said on numerous occasions that the script is complete, even after rewrites, so Im thinking this is being misreported somewhere along the lines. He also seems to know exactly what's going on in the film, so that the script would still be 'in the works,' has got to be wrong. But I like this Actress so that's good.
In response to David and Shaw being marginalized, I'm actually expecting it to be two stories interwoven. Like the new travelers are on their way to wherever they are and we are cutting between the action. This would also fit with the Paradise Lost connection, in the poem their are also two narratives, overall.