Vaping a 0mg nic juice is the safest option in vaping, besides not doing it at all.
Basically you might experience Nirvana. Also since vaping hasn't been around very long, it's effects aren't completely understood. If you don't smoke, it's worse for you to start vaping.
Though a buddy of mine never smoked, but he picked up vaping/dripping 0mg nic juice. He seems to be completely fine.
Regarding my post in the rules thread. Our lungs were not designed to withstand vaping/smoking. The risk of doing damage is extremely low as long as you pay attention to the types of juice you use and the ingredients in them. Basically make sure your vendor is only using VG/PG/Flavoring. You don't want to end up finding out that your juice has fake butter flavoring and is scarring your lung.
Basically if you decide to start, make sure to buy from reputable vendors.