Fun! The gravity is clutch. Controlling that ship is difficult. Maybe if you reduce the control sensitivity and the speed of the asteroids it will become more of a suspenseful and planned out thing. As it is at the moment it feels like a shooting gallery and you're the target.
As for the trading at the ports, I'm having a hard time remembering what's a high versus a low price because I'm running for my life trying not to die. Did you toy around with the idea of Class 1-8 ports like in TW2002 and discard it?