Hm, I've done some testing and it seems I only encounter an issue when using the "BigWorldSetup" program to install the mod. Installing the BG1NPC Project separately, even if using BWS for other mods, seems to be fine however.
I think I've attached the weidu.log but I can't seem to attach the setup-bg1npc.debug.
It seems the solution to my issue is to simply not use BWS to install the BG1NPC Project - I'm not sure if this is generally recommended or not, so my apologies if I'm treading familiar ground.
WeiDU.log