A good introduction to a criminal quest I was thinking is simply have some shady NPCs that hang around areas like the slums, docks, a dark corner in the bar, the Noer market or arena at night
Can be as simple as "Hey you wanna make money fast? Just sell me some (white dragon) weed." And from there it escalates in collecting loans from gamblers to then collecting money from whores not paying their pimp then eventually selling people into slavery and helping plan a mass prison break.
I'd be happy with a simple reskin of existing quests with alternate rewards or as previously mentioned a personality type or a gang brand/tattoo that caps morality to be no higher that 35 for the challenge