Ming, I enjoy your "Cyber Gensokyo" idea. But it might be a bit hard to set up, without stepping on headcanon toes and things like that.
My alternative idea for you is to come up with a setting idea that is Cyberpunk oriented, but with some sort of tweak that means that the protagonists are all cute girls. Even if it's a bullshit reason like "Only girls under 21 can see the DODECAHEDRON AIRWORMS that take over people's brains." or something.
If you want to chat and bounce ideas off someone, let mek now, and I can join the IRC and PM with you.
As for the DM thing, that's a bit dicier. I have some experience, but I'm not 100% sure how it'd work on here.