Thanks guys. I think you're both probably right ... I was probably "giving" the movie a lot. I tend to do that when I have low expectations!
For the revelation, I was thinking of when her ex-husband's old employer explained to her that she wasn't the reason he was fired, she never went on a tirade etc. I actually thought that the MC Concern was Memories (and I think in the storyform I picked, Signpost 3 came out as Memories too, which could've fit). But yeah, at least in the film, her blackouts were a HUGE source of conflict for her.
I thought the IC was a combination of the girl who was killed (Meagan?) and Anna, the ex-husband's new wife. Meagan's concern of the Past with her dead baby was obvious, and both kind of influenced the MC in the area of her past life, past relationship. Anna's concern of the Past had to do with the fact that the ex-husband wasn't faithful before... one of her lines was even like "now that I'm the wife, I miss being the mistress".
I think that was what I liked about the film -- I wouldn't say it was great, but I was left with the idea that the influence from the IC throughline was kind of cool, hardly any kind of argument or interaction between MC and IC other than "get away from my baby", but you could see how it worked. Well, mostly.
That said, I have NO IDEA when the story actually starts and what's backstory. That part of it was definitely messy. Is the First Driver when Rachael sees Meagan with her other lover, the therapist? If so, all the stuff months in the past is not any signposts, just backstory, and a lot of the films scenes' were in that backstory. Perhaps that could explain the story's issues, that so much of its time was devoted to backstory?