Still, I know the intention of trading being difficult was to make smuggling more worthwhile, to encourage combat potential with factions...
Still, I think trade should be made easier, and specially profitable if you have huge trading fleets (example: trading with a port huge amount of goods at once lower you tariffs), then encourage pirates to hunt those huge fleets, thus you achieve both objectives (trading become fun, with the more you get money, the more profit is your potential, but also become more risky, with larger cargoes attracting combat).
Right now you need to luck out too much, and is easy to get stuck (ie: you don't have sufficient money to expand your cargo space to use some opportunities, or don't have money to buy the requried goods... For example maybe you noticed you could profit 2000 per piece of some high-priced good traded, but you have money only to buy 2, making the trip not worthwhile in terms of supplies and fuel).