10 Lvl7 turrets! yikes, most transports have <7, except the Container Trans.
Also, all Houses have their own transports. Mammoth, Percheron, Behemoth, Bumblebee. They're all 2000-2500 capacity. If you wanted to go that route with House transports, bump the capacity up on all these, but maybe to 3500-4500. I still think the Adv Train should be the biggest in the galaxy, with the Whale and it's paper-thin armor second a couple hundred units lower, the CTrn, with 4600, then the house transports.
Corsairs and the OPG do NOT pirate those on humanitarian missions. I know this from personal experience. I have, however, come across some artard indie try and pirate me. I, in RP, calmly tell him if he wants to pirate me, his families will starve because I can't afford humanitarian missions all the time. Usually they let me pass. I jot down their name, and when I get to Gamma, mention it to the authorities there.
As for trade routes, there are LOTS of profitable routes into Bretonia, into Rheinland, etc. The problem is they take a tad longer for the power-traders (such a nice term for them). Liberty needs some tweaks, there shouldn't be ANY trade routes that max out there, it's the center of the galaxy, closest to everything. Hauling Niobium from Taus to Dresden should yield the highest profit, it's the longest route. Problem because all these blasted jumpholes and empty 'guard' systems that people use.
Now granted, I take jumpholes when I run Deut and Plutonium, but it's a good 15m trip one way, so I don't see a problem with that. I'd like to see Dusty through his weight around in this thread at what he's come up with.