There was a code change to the scripting language some time back that broke them. I suspect it was something to do with certain script types being changed to not trigger unless a) somebody is in the area or b) the NPC in question was flagged to always update.
I'm pretty certain that when the code change went in, I went back to Seawatch and (thought I) fixed up the NPCs and (thought I) tested the fixes work. But I suspect, in hindsight, that I missed something, and so the fix wasn't totally successful. There were plenty of updates to the scripting language subsequently that could have broken things further.
Certainly, by the time I returned as a player it was pretty evident that the town wasn't working properly. Pretty certain I bug logged it myself, but perhaps not.
The scripts in Seawatch are complicated as hell. An early effort on my part, and replete with the sort of mistakes typical of an amateur coder, I suspect. My recomendation would be to remove the shopkeeper and shopdoor scripts, plus various other broken "features" (like the corpse collection service) and leave in the town gate open/close script. That's probably the quickest fix.
It was a grand experiment, but it wasn't exactly future proof.
I'd happily offer to come back and fix this one thing myself, but that probably wouldn't be appropriate
But it goes without saying, Zav, that if there is anything I can help you with by way of info, etc, you are of course welcome to give me a shout.
-Tat