The biggest problem with the "hostage" situation is that it crops up about 18 times a night. System comms almost invariably has something about some guy hidden somewhere cackling about how he's slowly torturing "ur mans lol" and launching them into space/etc.
NPCs in your cargo hold don't make for fun.
-Now- something that is cool (which I've never gotten a trader to go along with, bloody peasants) was something that once went down with the Xenos and the .:J:. where we had one of their guys on the wrong end of several guns... To find that they had another Xenos in a similar predicament in another system.
So we swapped.
Was bloody fun, no powergaming. No "I haz da admiralz" and no real problem with it happening 28 times a night.