That was some exceptionally competent Kogoro, he didn't stumble at all during the deduction. I wonder if the others found it weird that he didn't "sleep" as he usually does.
It sure has been a while since the program that guy made for the BO has been relevant. I remember the first time I read that part I was at school during a break and became really curious about what it could be. Now I've been out of school for over decade...
When her obsession was revealed it didn't feel too crazy to me, not because it wasn't but I'm just used to it from seeing things like that in several other manga I've read. This however, takes it to a new level.
While I like the theory that she's just pretending, I also like to think that she actually is under the spell but it's just that her desire for vampire girl is stronger than the control spell and overriding it whenever needed, so basically: horniness > spell.
That last panel definitely is a relatable reaction to having woken up from a really great dream and realising none of it was real, also love the others reacting to her dream delusions.