Craig's basically nailed it. Tormax is being given a lot of leeway because Trax finds him highly amusing. But Trax also knows he's in a bit of a bind. Were this trip not urgent, Trax could fly the ship himself, but getting there quickly requires a skilled pilot. That also factors in to the negotiations.
Having said that, if push really came to shove, Trax would have no problems blasting the kid's kneecap to make his point. It's one of those little quirks that makes him so lovable.
