1.Humanoid creatures created by another God. There's only one alive with that essence. Ayako or Annie from HTA.
2.Yeah, I almost forgot about that one.
3.A drug that cause hallucination and makes one appear mentally sick.
4.Every thing is summarized well but a few things I would like to add. Rose was 29th baby made from Dahlia's eggs. That disintegration part was written back when I was reluctant to reveal secret stuff about the game. In reality Takemoto focused all of his resources on researching the alive ones.