And speaking of unbalance as mentioned in the first post, I didnt get a reason yet.
If you want to counter pirates, take a battletransport with you. Slightly less cargo, but is not that easy to take down. So, it is balanced now, transports that can effectively take down anything less than a gb, if flown properly, are available in game.
Coming to cruisers, they are slow, and you can easily strafe/EK/cruise/whatever to the nearest base or even, engage the cruiser, if you have a good enough armour, and maybe, come out victorius. I know of a BWT killing a cruiser(Lyth, I am watching ya).
And if you are speaking of battleships, just fly away, as they dont have Cruise Disruptors, if their demand is awkward. They cant do anything but watch.
Spot out the thing that is not balanced in here. Traders have a choice to either earn maximum(5k'ers) or effectively fight piracy on their own while earning a decent amount of cash(battletransports with 4.2k). But, at the end of the day, a trader is a trader. And your role is to trade/be afraid of pirates. Not to be a war hero, by going out all guns blazing on the pirates. Defend when you can, for you have the options to that too.