I imagine you may have already thought of this, but it might still bear mentioning- Have you considered a Scribblenauts style? In other words, first you have the various traits for the characters. Their high stats, their afflictions, perhaps even a few unusual tags- There were tendencies for characters in King of Dragon pass to bear unusually powerful grudges against certain magical creatures, for example.
Then, you take the events, and determine a series of useful triggers for it.
I've done a quick event to get the feeling for it here, and I got 'can I keep him.' I've got three heroes, one the matriarch with a great deal of martial ability, one a diplomat, and one a fellow with a good amount of trickery. So, let's say that our diplomat also has some trait along the lines of hates animals or beasts or whatever. Let's say, then, that this has three 'triggers'- One, a martial rating of <x>, one a Diplomacy rating of <x>, and one the 'hates animals/abominations/whatever' trigger.
The matriarch might recommend that we kill the creature, or if it can potentially be powerful in combat, she might be telling us to keep it because it'll make life more interesting. It really depends on the game developers here to figure out which would be best.
The diplomat, you can have a random number generator, or just have a 'random priority' assigned to the 'hate' personality traits. Say, a number from one to 100. Then have the threshold between the required amount and their value- Say, the required value of 'Diplomacy' is 45 and the required value of 'Hates animal' is 60, if they have a diplomacy of 70 and a hates animals trait of 75, then they'll give the diplomatic answer, against their prejudices. If their diplomacy score was only 55, like my character is, they'd say to hell with diplomacy, kill the filthy little beast. This is one of the more complex methods, you could just as easily simply have a random number generator flip a coin. Heads, they advise diplomacy, tails, slaughter. Of course, that would make them seem a tad capricious, but that can be interesting.
The tricky chap, with no important triggers, can just spout out some random thing related to his personality traits, generic- 'Sounds like a good idea to me', or some randomly selected proverb, or just a bit of background information. Something on why the heck the kid found a puppy with a snake-tail, capable of turning people to stone.
Hope this is helpful and not a horrifyingly obvious idea.
