Buffing some spells?

I'd be very reluctant to buff one of arguably the best classes in the game. Turn Undead has never been a particularly strong ability, both in NwN and 3.5 as a whole but even a level 5 cleric has the option to fear 2+ undead, more if they have the Sun domain. Something like that is really valuable for an act like securing a safehouse. They can use TU to buff their damage/AC via Divine Might/Shield, and their spell list gives them among the most utility in this setting along with crazy PvP options. I wouldn't want even a level 8 cleric to have a "press button and they die" ability. Siranda zombies are supposed to be markedly stronger than the average zombie.