In the different towns and market places there should be random pilot groups or gangs that you might accidentally bump into, causing them to challenge you to a skirmish. So I guess it would somewhat be resemblant of a Pokemon battle. You cross their path, they challenge you, you lay the smack-down on their puny ship, and you earn a little cash for winning (though you don't send any home to mom).
If you continually fight groups in a city, perhaps they'd become stronger/more abundant and you'd kind of end up fighting underground factions and gangs when you visit the town. And as you beat more of them, they'd channlenge you more in bigger, stronger groups.
Basically what I'm suggesting is some way for you or an AI to initiate a skirmish without it being a "quest", but rather just a one-time fight.
