The idea is interesting and the story even seems good but... Oh my god, I hate these trashy comments... Is it really necessary?
I already get annoyed by genuine comments praising trashy works and speaking ill of works of art. Now, even within the story, I have to read comments from people with bad taste or homophobes? And honestly, I hate the idea of her being influenced by them and by the book's rating. It has an exhibitionist fetish vibe.
Ultimately, what's the point anyway? The story has nothing to do with what she was writing in the novel. Even she doesn't understand the world she created and the characters. The sisters' love and interaction went from 0 to 100 very quickly, and considering the grading system, she'll keep going back and forth between being a villain and loving her sister. And the existence of this shitty system will basically prevent a true immersion in the story and the feeling that this is real life now for the protagonist.
It's as if a perverted GOD is simultaneously punishing her for writing badly, but also making everything Yuri because he likes it.