I know I'm a page late (and honestly other people did a very good and detailed dive into it too!) but yeah in addition to all that, the RL stalker this was a big turn off.Wow, even I'm a big fan of Maya and I know that Noriko is going to be very important to the story, why do you have this opinion about her???
Also, to go a little more meta on it, I remember when she was first introduced Sel doing a post somewhere to the effect of "if the perfect girl doesn't exist you create her, meet Noriko", so when she was so unhinged during her intro scenes, I was already on alert. There was also some other Sel comment when someone was asking him about the original plans for the story if the second floor hadn't gotten added, and he said that Niki would've still happened and been (obviously) vital to the story, but I assumed from that point that Noriko was basically shoehorned in. To be fair, this was all quite a while ago and I might be misremembering!
In general though, I feel like most of the characters besides the original 10 are unnecessary and contribute to bloat on an already insanely bloated game, even the ones that I've come to really like. Uta is probably my favorite of the main cast, but her story is pretty much a nothingburger with a crazy amount of stringing along. This is what happens when the author takes so much pride in word count though