You're right. I actually stated beforehand the cause of the explosion... twice! Once in Chapter 7 and once in Chapter 12. The chaotic nature of my writing has torn yet another plot hole in the fabric of the space-time continuum. That is the Maelstrom way.
I agree there's lots of room left for developing the biological nature of Creative Sparks. I think connecting it to genetics is a good starting point. It also gives more meaning to familial connections and can be used as an explanation for things like twin telepathy and dream sharing.