The list of good and bad traits is a long one, and you have to do a bit of searching for it on the web or by finding the right plain-text file in the game configuration folder that defines these traits (and then making sure you only add the good ones). You can easily set the age of any character and change their stats, but their traits need to be added one by one. Even though the game provides all the in-game cheat commands necessary to achieve this, it is not as easy as one may think.
Nothing short of the most over powered ruler possible is acceptable. I had started playing Crusader Kings II again and like every other time before it, I always get to the point when I want to mess up with my ruler, i.e.
