Love the idea of comparing Charlie and Ethan, but I know what you mean about writing Claire in that head space - I've set myself a challenge of writing something along those lines (as a chapter in an epic fic about how series 2 might have been different if Michael and walt missed the flight) and it's not easy, maybe because I did feel some sympathy for Charlie during that storyline and like you say I wasn't angry at him myself, what I am trying to do with it is write some backstory for Claire explaining why she found it so hard to forgive.
But anyway, loved the story!