regarding the Merchant.. in my game he was not so far away from the big "tree boss", like 500-1km away to the north east.. But this location was like 1½ day of sailing from where i started the game, so VERY far away. But its random in every game, but he spawn in the same biome as far as i know. ( biome with big trees, i know there are several such zones but it will narrow it down a bit where to look. ( maybe named "dark forrest area ".