Personally, I would say if anything trading is way to easy in this game. You just run around between villages, buying minerals and silver for anywhere under 100 (usually more like 30 each) then sell them at almost any town for 200 and certain towns that will pay 3-400 each. Ireland actually has some rather cheap hides and stone that you just ship over to England and sell for 2-3x. Also, you don't need to buy a ship unless you want to attack pirates, or be a pirate. Theres a ferry lane at Lynn , a village of Gwent I think? The red country in Wales. its a 2 hour trip, so 20 coin and you're back on dry land. If in Ireland just head to the coastline directly east of that village's little peninsula.
As far as troop training goes, I will say its a tad bit ridiculous that raw recruits come out at lvl 15. This in turn makes your training skill useless until you hit lvl 16, and honestly its not extremely helpful until you can train tier 3>4 at lvl 24. I would like to see the troops' level come down 5-10 levels. On the flip side though, recruits are quite strong.