What you are asking can certainly be done, it will just be immensely time-consuming. What you will need to do is open export_descr_character_traits.txt and add or change the traits you want - then you will have to adjust the triggers that cause these traits to occur. This is the trickiest part because of "tokens," the conditions that cause the triggers. I dont know if anyone outside of CA itself has a full list, so probably what you will have have to settle for is trial and error.

Good luck though, and welcome to the immensely frustrating world of modding!