The nova problem isn't really a problem per se.
Actually, this entire disagreement is a simple difference in playstyle. NPCs aren't "monsters" or "encounters". They are actors in a world, and if it brings them into hostile contact with the PCs, then so be it.
EDIT:
Throwaway NPCs like random city guards would have rough notes sketched out for them and I just fill in the blanks on the fly by looking at character creation rules.
Non-throwaway NPCs do actual things and I do need to know their abilities.