These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Cliché Storm: Yeah. This is a bog standard magical idol singer story with no hint of self-awareness.
Creator Killer: Tokyopop's over-focus on this project despite poor sales and negative critical reception is believed to have been a major part in their eventual downfall.
Mary Sue: Ai, very much so. Not only is she a self-insert of Courtney Love; she's also a flawless singer (by the end, she's the biggest pop/rock star in the world), gorgeous babe who everyone hits on, a special Half-Human Hybrid whose very existence ends the war in her land, can calm down dogs just by looking at them, cure people's suicidal urges, turn bad guys good, has multiple love interests, has a temper and constantly badmouths people but somehow still always gets attention and approval, doesn't want to be signed onto the biggest record label in Japan, the list goes on...
The only people who dislike her are the Gorgons, who all turn to be on her side by the end; Hikaru, who ends up liking her; the H.T.A. studio exec, who doesn't exactly dislike her, he just wants to use her for his evil plan, and gets arrested in the end anyway; Kaz, whose thoughts about her by the end are unclear; and the group of people who literally think she's the devil, who are joke/parody characters anyway.