This, I know, doesn’t speak to all of Jonah’s questions by any means, but here’s what Raymond Arroyo had to say about the whole thing after interviewing Gibson earlier this year. Seems to me that some of the “problems” Fredriksen brings up in the article you cite are not essential to the story being told. Historical accuracy, to the extent possible, with a focus on the suffering of Christ, appears to me is Gibson’s goal. Arroyo’s interview with Gibson can be viewed here (scroll to 15).