Is the Nissan versa good for mountain driving?

It all depends on how you drive the car and what you expect it to do. Just looking at it I would say the farthest "off road" you are going to go is level ground with no ruts due to its ground clearance. It will probably get you where you want to go, but you are not going to haul much due to the car's size. If you overload it while at lower elevations, as you get to higher elevation's the car will be under more strain going up (powertrain wise) and put extra strain on the brakes coming back down.