BTW, I don't know if anyone has mentioned this theory yet, but I think that the climax has to involve good Cooper, having escaped the Black Lodge, going back in to confront Mr. C there. That would resolve the prior failing of not confronting the doppelganger with perfect courage and also give Cooper the opportunity to…

Thanks for reminding me about the two diaries. But this seems to account for missing pages of both diaries (found by Hawk or sent to Donna). So these would need to be pages not previously known to have been missing?

(1) By the time of Laura's dream, hadn't she already handed the diary to Harold Smith, so there was no diary to write in?