Is it harmful to plant vines on the roof? Will the roots of grapes drill cracks in the wall? Is it harmful to the fence

Better not. First of all, if you don't consider planting plants when building the roof, you won't make a waterproof layer specially, and the load-bearing capacity can't be calculated. Then if you plant plants on it, it will definitely destroy the roof structure, the roots of plants will corrode and puncture the roof, and the roof will leak if you water it frequently. In the same way, so is the root of the wall. If the waterproof layer is not specially made, even if the root system will not destroy the wall, just watering will lead to the resurgence of the house.