1) At the beginning of the comic, we see Gordon sitting on the train, hating himself, hating the city, fearing his unborn child. He starts as a reluctant hero, reluctant to be a cop, reluctant to be in Gotham, reluctant to be a father. He realizes how corrupt the cops are in Gotham and is shown his task, what he needs to do. He doesn't want to fight, but when his family is threatened, he's given the motivation to take on Flass.
2)
It's in this panel that Gordon struggles with both his, and the Batman's identities. Here, Gordon grapples with his mistake regarding Essen, here, he grapples with the alignment of the Batman. Hero or Vigilante? At the end of the panel, Gordon comes to realize that the Batman is there to help, a hero, someone who, while frightening, uses the fear to combat an even more fearsome enemy. Gordon realizes that he has to be more than just a cop to bring justice, and that justice is the end goal, regardless of the means.
3) There is no Batman without a Commissioner Gordon. Adam West, Christopher Nolan, the New 52, Gordon is essential. At the end of Year One, Gordon realizes that role. He becomes part of the Batman's team, along with, apparently, Harvey Dent. In the end, Gordon confesses his mistake to his wife, he saves his child. He finally knows who he is as a hero, and accepts his hero's journey. Cop, father, hero.