Here's a tip for beating the cops while you have that valuable cardamine in your hold. When you're traveling in a trade lane, select the docking ring or space station where your headed to before you exit the tradelane. You can usually do this before you come out of the last trade lane ring. As soon as you exit the trade lane hit goto, if the police scan you, they usually won't have time to do anything by the time you dock. Don't respond to the drop cargo message, delay as long as possible. You're usually docking by the time they decide to do anything about it.
Also, to avoid the cargo stealers, you can use your overdrive and then kill your engine. You'll coast at 195-199 and their cruise disrupters are useless against you. You can stay in "killed engine" mode and maintain the high rate of speed by hitting the overdrive every second. Your speed won't go below 197 once you get practice at this. You can also do a good amount of manuevering everytime you tap the overdrive key so it can be used in asteroid fields.

In the rebalance mod you can use "engine kill" mode to fly everywhere. It's superior to cruise speed because you can get to 450+ drift speeds with the right engine/thruster combo. Nothing can touch you, cops are never fast enough to catch you when your coming out of a trade lane clocking at 450+ speed.

Good luck on your pirating carrer.