I'm not a geek myself, but I live among them and I always thought of Snape as pure geek, from his long greasy hair to his refusal to suffer fools gladly. The transition was surprisingly smooth.
It's interesting that you picked up on the first "incendio" scene. It wasn't in the original loose outline; in fact the line itself was suggested by Spider's idle threat a few lines earlier. But when I wrote it, the whole backstory sort of fell into place for me.
Thanks for the recs, but more for enjoying the story.