I have read the rules and searched the forum, and I can't find the answer to this...
Do NPC's get keys? Do they gain experience? Do they advance?
Um... my first instinct would be no. They're NPCs. If the GM wants them to change/improve he just does it. It's the same way I handle NPCs in D&D or anything else for the most part. Perhaps I'm missing something in the way Shadows of Yesterday works though. A more expert opinion might mean more.
NPC's don't get experience, so having keys qua keys doesn't make a lot of sence. However, writing down key's for NPC's as a guide to their behavior and motivations makes a lot of sense.
-K
Big ups to Kingston. I'll write down a key or two if I want some motivations. Otherwise, I just advance NPCs to match the PCs power level as they increase.