Hi, Niklas! Those ideas of yours sound interesting. I especially like your idea about Manny seeing his life flash before his eyes (er, sockets?) in the train. I don't know how well such an idea could be done and kept true to the hert of GF, but if there ever was a prequel story, I think that's one of the best ways to approach it.
You seem to know your way with English. Why don't you write that as a fanfic?