Chapter 14, where Plankton says that Karen, and not C'ren, is the only woman he will ever love, and that Karen was the only one who believes in him despite the fact that he sometimes took her for granted. He also said that he looks beyond pretty faces when it comes to women. That has got to be the most well-written part of the fanfic, excluding the last chapter. Even the author himself thinks so.
C'ren's half-brother's true motive of making her listen to rock is to alleviate her pain. He is actually an insecure, aesthetically-challenged boy who gets failing grades, is obese, and is being bullied. Add that to the fact that his mother is forcing him to rape his half-sister. In a way, this is heartwarming because he is actually attempting to empower his sister by making her listen to the same music that makes him feel empowered. She, unfortunately, took it the wrong way.