Work continues on the Dark Mod map, and the more I play around with DarkRadiant the more i appreciate what you can do with just waypoints and triggers, without even touching actual scripting per se.
I have an NPC shopkeeper who has a routine of manning the counter of his shop, but at random he'll go upstairs, turn on the light, go to his safe, open it up, and check the contents. If the safe is empty, or if anything valuable is missing when he comes back downstairs, he goes to full alert. With a little bit of effort, making varied, unpredictable routines for patrolling NPCs isn't as difficult as I thought it'd be.