Being evil doesn't always mean being a reckless slaughterer. That's more chaotic evil. There are evil choices that can actually work to your benefit here. For example, as Synaryn said, you can save Sazza and join the goblins. You can side with the druids and/or help the tieflings but ask for rewards every time. You can help the tiefling kids steal the druids' precious idol (not sure if that one is actually evil or more neutral, though; the druids were pretty mean to the kids). Finding Halsin and killing the goblins can be done in pursuit of monetary reward:
Not every evil action is punishing.
