it sounds like a good practice. And as to the danger, there must be some parts of the western world that are free from safety restrictions...
What width of bark do you need to take off? I've heard of trees recovering from ring barking if the cuts aren't wide enough - the bark re-bridges
when we do it it is just the with of the saw chain. we havent had this problem on the jobs we did but you can also double ring it or use chemicals. make sure your cuts line up all around the tree too you dont have to cut very deep just the cambium layer.