Explosive shot, explosive shot and more explosive shot! Farin's explosive shot is the most ridiculous and overpowered skill in the game, killing everything in one shot, except some bosses. Uses just 1 bolt, some power and has a quite short cooldown, insane area damage and makes Farin the most damaging character out of the three.
There isn't much use in pumping Dexterity, as the Explosive Shot's damage is so high, it doesn't really matter if you deal 150k or 250k with it - even if you don't kill a troll or a boss in one hit, you can simply wait a few seconds to fire it again. Because of that, and because not many skill points are required for this, any Farin build is still better at range than Andriel's or Eradan's. Using Mithril increases Dexterity anyway.
All that aside, there are some other ranged perks Farin can utilize: he uses crossbows as a ranged weapon and the difference is, shooting an enemy with a crossbow will trigger a recoil on the smaller (human-sized) enemies, meaning it can interrupt charging enemies or help an ally who's having trouble fighting one. Also the Heavy Bolt may knock regular enemies back and on the ground.
Crossbow Adept is a good skill to max if you like shooting, it allows you to burst down enemies like archers or spellcasters, so you don't need to spend an Explosive Shot on a single weak target.
After firing with the crossbow, Faring will immediately reload it, so the crossbow is always ready to fire.
Crossbow Adept, Heavy Bolt and Explosive Shot are the only ranged skills available, and even if you max them all, you still have plenty of skill points left for a melee build. Probably the best crossbow in the game is the Jewel-Smith Crossbow, with x1.5 damage vs Orc and Undead, but if you're using explosive shot, the extra +50% damage won't matter much, so it's better to use any other crossbow with similar or higher base damage, but with other bonuses.