I must admit, I didn't find a use for any of the skills, and I would not even contemplate playing a Survivor.
The game is very combat heavy, and it seems to me that any character who cannot pull their weight in a fight is just not worth having.
I do not believe there is any point in the game where a Survivor could honestly be said to be more useful than any other class - yet there are certainly points where the Warrior and the Mage excel.
The fact that the Lock Pick skill is bust just makes it worse.