That's an interesting question indeed, specifically: would easy access to legal weed reduce property crime in the area (for most of the crime seems to be smash-n-grab property crime).

My suspicion: no, no change. For all intents and purposes weed is legal in Vancouver. You have to be pretty out of touch not to be able to get it. But weed is cheap, and non-addictive (physiologically anyhow, I suspect the jury may still be out on psychologically; IANAP). I would be surprised to find that anyone is committing re-occurring petty crime to buy weed only.