I actually found the Merchant pretty easy (I mean, after I got the hang of overseas trading and everything) and now it's my best hero (level 10, woo!). You should create a Merchant that's friendly and a haggler. Basically, befriend the people who come to your stall and then do the compliment taste, butter up, hustle and ask to buy goods. Each day check what is the most popular merchandise and buy it (especially if it's something expensive). Stock your stall with only the popular merchandise at first so you'll sell it the fastest, then with the rest of the merchandise you have to sell. Collect plants and herbs; fish a lot; if there's a larder in the throne room, steal food from it because the Monarch hunts bears a lot.
The hardest profession for me is the Jacoban Priest. I really want people to fear the Jacoban Church, but I suck at making them scared.
Spies also get pretty annoying for me, if they get caught and are sent to the stocks.
