I am not native English speakers and I do not know too much from the English-speaking people's language habits, however, the peoples in my home in the Middle Ages was available specifically for a wide vocabulary to express their disapproval.
Then why could not to swear too gaudy the people of Thedas? (Yes, even the nobles, but maybe a bit sophisticatedly ...
) Maybe the problem is that a wider vocabulary should be used. To make it more colorful. Otherwise, some of the "medieval" fantasy book / game / movie uses too many times the modern terminology, which can be disturbing the emphaty. I do not know on Englis language it is disturbing or not, but on our language it is sounds bad. Summa summarum: Lets write authentic curse! Then I'm satisfied.
(Sorry for my weak English)