Merchant: Greedy and Haggler = Permanent happy Drunkard, just put a barrel outside his house most of the time he stands there anyway for selling.
Wizard: Evil is a good one, just cast a driveby Magic Arrow on some random dude and evil laugh at them because he got wounded from your spell.
Creative Cook and Excitable is a good combination, both of them get an extra focus buff when cooking meals with ingredients.
Hopeful Orphan is a good trait for everyone, the third person you ask about your parents gives you a letter which you can use for a 12 hour +30 Focus Buff, it isn't even an action the buff just shows up. The letter can be used unlimited times.
Uncouth is a good negative, there is no negative Focus buff from that one. Sometimes you screw up in a socializing action but thats all.
Make one of your Heroes Bloodthirsty and when he is not your active hero watch him as he walks through town and beat random people up, priceless.
Avoid Insomniac and Fool, those gives you a really hard time when questing. The Fool might loose his walking destination at random and the Insomniac just falls over and sleeps at the most inapropiate time.
Drunkard is easy to please, just put a barrel in his house.