I was thinking that besides some of the other ways you want to fix things mechanically, maybe there's a rules/D&D way to help change things a bit too.
I was thinking for ALL
NPC spell casters (*IF*
there AI is good enough) 2 spells:Daylight
- Would basically turns vampires into ashes.
&Earth to Mud
- Basically turns stone golems into pudding.
Now, I'm not sure these are even in NWN2 (Or that Earth to Mud is a real spell, lol) I think Sunlight (Sunbeam?) maybe in the game already, but that's not as strong as Daylight. Daylight is basically a level 3 spell everyone, except warlocks I think, get.
Earth to Mud you could basically make the same as Daylight, but switch it to golems instead.
So, I guess it depends on how you want to try and work things out too Brumm, and how much work is involved as well.
: Almost forgot about Dispell
to un-summon the summons. Or, at the least, maybe to interrupt the player's control over the summons and make them hostile to the player. You farm with the summons, something turns them hostile, and the player gets killed. Just some more thoughts.