1. For normal classes (so, yes, there are normal classes) it's the same as most schools, but classes related to powers would be divided up based on firstly, how good the character is at controlling their powers already and secondly, what level of school they're in. So...it's possible that a 7th and 9th grader would be in the same flight class, for example

2. I might answer this one later, ehe. It's...kind of a little late here.

3. That would differ from character to character, but I'd generally recommend asking other players first if you want your character to know them beforehand.

4. There's no overarching plot in mind. I have some events and such in mind, but it'd be fairly easy for people to ignore them if they want to focus on character interaction/do their own thing. And as I said in the OP, I'm completely fine with players throwing their own events or plotlines into the mix, so long as they don't clash with the tone of things and people have the option to stay out of them if they want.

5. Honestly, I don't think I've heard of Project K before now and...I think the idea was influenced by Raildex, but more in the sense that a friend of mine who's a fan of the series suggested the school setting when I was still trying to work things out. I hadn't really seen/read any of it at that point so I guess from my perspective, that was more of a Maken-ki influence, I guess. Well...minus the excessive amounts of fanservice. But um, yeah, initially it was...basically, it started out as a combination of, as Rin said, Kamen Rider Den-O, Kamen Rider Double (to the extent that one plan for the initial concept would basically copy the villainous organisation from that and have the players in the role of detectives) and...probably some other stuff I can't remember at the moment, ehe...I think maybe Fate/?