I was thinking of my own SDK project to move Goverment choices to a SMAC style in which the player chooses high level options which do not have direct effects but rather give a +2 or -1 to underlying "meters". The meters then determine the bonus or penalty.
Your proposed system sounds to be much in the same spirit with choices esentialy adding or subtracting from a meter. An interesting interplay between leaders and goverment choices could develop say you have a leader who gives you +2 to your Economy that combines with your FreeMaket that gives +2 as well and now your Economy is absolutly Roaring.
Overall the leader should probably have an impact sligtly greater then 1 social setting (gov/legal/econ..).
Also you might consider a mechanism for balancing leaders overall quality, sum up the relative level on each trait family from the negative stuff to the positive "super" option and compute a value. All leaders should be made to equal that value so theirs less chance the following choice.
Lord Howard the Stupid, Cowardly, Incompetent bedweter
Lord Richards the Brave, Noble, Fearless Concourer
Not adsactly a very "interesting desision"
Now the other cool thing about equalized leaders is that we can easily make the equalization value an XML based atribute so players can adjust how powerfull an effect the leaders have on the game.