I never had any real problems with nwn. (not at all in oc/sou) Only on godspire it seems different.
This probably is because trueseeing isn't enabled (crashes caused by poeple comming out of stealth), the frog that is disabled (you see more, more can get you crashed), and the somewhat high amount of players with all their visual effects (hellball for example) in one single area.
It's a lucky discovery that setting the animation of the characters back like they were in pre-hotu helps against the crashes. And the amount of crashes on GodSpire probably will go down if the visual of hellball gets changed to something more nwclient-friendly.
For sure if you have a randomer running around that does nothing else than firing that spell while (ab)using the healinglights evry few seconds.
-Mel