Trading in Europe is easy. Just go fief to fief around the map in a circular fashion and buy 249 goods when you can and sell whenever you come across a fief and your goods are over 300%. You just wander with your maximum crates, and after you sell 249 or so, you just buy more at the next one. I was carrying about 1500 goods at a time and still moving quite fast.
In North America there were few free trade fiefs, and the distance between them was greater, so I'd just go back and forth across the map, then sit and wait if there was no SD available. As for the dumping of goods, it works within a small faction. The guy who's tied to his fief can sell it when best to keep his SD at reasonable levels. And he gets half the money, which usually goes into one big pot anyways.
Also small factions loomed what they needed, starting with the cheap stuff cuz that's all they could afford at the beginning. And while you could make a deal with a neighbouring faction that you'll loom 2 handers and polearms if they loom 1 handers and shields, but if you happen to go to war with each other it could make for some pretty crappy battles.
But crime is a bitch. If you can't control it due to lack of money or trade partners, you lose your garrison. You lose your garrison anyone can walk in and raid your fief. I'd say make crime hurt the citizens rather than the garrison, and only up to half the population can be lost. And get rid of raids altogether. What exactly was the point of them any way? So people can have one exp battle, then a peasant slaughter 24 hours later?
So NA is shittier cuz it has a lower population, less fiefs, less silver and more crime (at least compared to EU when it was active). This is sort of historically accurate. We're a backwoods population, like Scotland in medieval times, or the barbarians circling the edges of the Roman Empire. But what we lack in gear and equipment we make up for in ferocity.
