I just want to point out how biased and poorly worded this essay is. She was evaluated as an object rather than a human character.

About the paragraph on selfishness: Everyone in this anime is selfish and rightfully so. Otherwise we would not have Mawaru Penguindrum; we would not have relatable-- and more importantly human-- characters. Shouma and Kanba want a dead sister to continue living so they were at each others' throats for most of the anime because they had different ideals. In the beginning, Shouma could care less about Ringo's actions and wellbeing and don't get me started on Kanba and Himari. Ringo didn't owe them anything. She didn't owe them her diary. Shouma wanted her diary to save Himari. He could not care less about her little "fate" mumbo jumbo.

The paragraph on her not living for herself: Living for oneself is a very vague way of describing Ringo's decisions. Ringo lived a happy life with her parents during her childhood but things don't always stay the same. One of Ringo's issues was change. She could not accept it but she could not prevent it either. Key: SHE-- HER actions and choices-- could not prevent her parents from splitting apart. Desperate times call for desperate measures right? When a person's actions fail to result in their desired outcome, they stop trusting their own decisions. Layer that with desperation and that's when the diary kicks in. She began to place her trust in fate-- and more specifically, Momoka. However, her perfect plan broke apart when Shouma came into play. He detered her from the path her diary had laid out for her. I won't go into details about this because I think you get my point, but that's essentially when Ringo began to learn to trust her own choices again.

About Ringo being unable to empathize: Refer to previous paragraph. She was incapable of seeing the events and people that were around her because the diary did not acknowledge their existence. Remember, she was following the life the diary had laid out for her. Anyone not acknowledged by the diary will not be acknowledged by her. 

Regarding her father: Ringo felt betrayed by her father. However, she still loves and desperately wants his acknowledgement. Somewhere in her mind, she doesn't want to believe that her father abandoned her, which is why she still followed that diary religiously. She believed her family could still be saved. So her blaming her father's new family is just a form of self defense; denial. In the anime, we see her gradually coming out of this denial episode by episode--literally.

Finally, her fantasies: I do hope you realize Mawaru Penguindrum is an anime that is entirely comprised of symbolism. It is ridden with postmodernism elements. If it's not symbolism and she's actually fantasizing, it's her self defense mechanism kicking in. Whether she's fantasizing or if it's all pure symbolism, it all ends depicting the same thing. Ringo feels the need to disconnect herself from things she doesn't like. By imagining her parents as otters and kappas, she dehumanizes them. She can escape from the unpleasent situation for a while. She feels abandoned by both her parents whom stablized her (evidence from her unstable life without them). This is why she seems to have such a child-like psychology. Her self defense mechanisms have forced her to turn inwards when she's faced with situations she doesn't feel comfortable in.

Shouma is the catalyst for her change. He attempted to connect with her and became a solid existence in her life. This brought her out from her linear and fantasy-like lifestyle and forced her to acknowledge the world outside of her own. She felt secure enough around him to slowly bring down those defense mechanisms. There's a lot more I could say about why Ringo is who she is and why she does what she does, but I think I'll leave it at that.