The deadlift itself is not the cause of injury....poor form is. The heavier weights used do increase the "risk", but if you pull properly it will not be an issue. Having a "pretty"(not strong) lower back and abs is the real issue. And not strengthening those stabilizer muscles, by taking them out of the equation with the Smith, is a bad idea..IMO.
Why is it that a majority of bodybuilders are always looking for ways around exercises. They want to modify exercises so that they are safer. Why not just learn to lift correctly?