Part of this subsystem involves rewarding players for doing things that they find fun and interesting. One of the problems in traditional D&D is that the reward system revolves around interacting with and usually dominating the game world. You get XP for exploring dungeons and eventually for building strongholds. You do not get XP for helping your fellow players develop the story or for sowing interesting and dramatic strife among the team. You're basically leaving out rewards for half of your players out there.
Hence, the idea of mini-quests. Mini-quests are tied to one's humour. You get to open one quest for free in your primary humour. You can spend a perk (you'll have 1 to 3 perks if you have an above-average score in a trait) in any trait to open more if you like. Completing a quest yields XP (or perhaps some other benefit, like "Fate Points" if you care to use them). However, if you abandon a quest, however, there's a chance you'll lose an ability score point (you can get them back upon level up), similar to the effects of a grievous wound or major defeat.
Over the next few days I'll post my tables for each of the four humours.