Opening chests and collection random junk of the forest floor is generally the faster way of earning money. Stuff like Truffles and various Gems sell for decent amount of money. And yes, the Bard class is mostly for social interactions and doesn't have any combat capabilities, but then mobs don't really drop much in terms of expensive loot, so farming them isn't very efficient money wise anyway.
The prisoner's bodyguard could only be met if you had the Climbing spec from the Athletics Skill at the very start of the game. You had to climb up some vines near the camp before leaving the map, otherwise the guard runs off after you leave the map. Don't worry about him though, he wasn't really important or anything.