This is an action RPG, though, so it's light on the sneaking elements. You can sneak closer to enemies if you put points into Ranger Stealth and have a bow equipped, and you can turn invisible with a spell. You can lockpick chests and such.
But as far as being a rogue in town, no one cares if you loot their house right in front of them, and there's no real way to avoid combat forever (nor is it a good idea to do so).