My favourite profanities were the Lore-specific ones, i.e. Khlegar Ironfit's "By Tyr's right buttock!" battlecry (NWN2) or the most common "By the Nine Hells", or even race-specific for elves as "tree-worshippers". They were funny and added flavor without going into uncomfortables of modern profanities. I am sure there are plenty of creative ways to come up with curses and profanities that would reflect the world of Abeir Toril.

"There are three things that are strength incarnate: there is love of life, there is fear of death, and there is family. A family that loves death would have a strong pull indeed." - Tamoko