You do have to buy/loot arrows and bolts, and i don't know why it didn't come with the cheat codes, but i never used them because i love that game, its so damned good.
I found the quicker you are dealing with hostile "archers" the more loot & supplies you get from them.
Yeah .
I found it good if you're in a battle to get your thief/rogue to stealth behind the archers and stab em in the back whilst the melee fighters are fighting with your men, you can wipe out the archers without getting touched.
Did you guys install the player-made patch that provides infinite stacking? It makes it easier to carry around many arrows and you don't have to worry about reloading your quiver as often... I played a human ranger/rogue/wizard and found this VERY helpful since taking time to reload can be deadly.