Please explain _The Raw Shark Texts_ by Steven Hall [Spoilers]

I don’t get it! What exactly happened?

Did Clio really die? Did she not die but went to conceptual land to await Eric?
What was meant by “You div.” in her note?

Did Eric the first really succeed with the Ludovician and bring Clio b ack?

Wasn’t it Fidorous’s body that was discovered as Eric?

Were’s Gavin?