As far as risks go, yes, dressage would be considered less dangerous than jumping. There's far less of a chance for the rider to fall off when not jumping over obstacles. But you have to remember that riding in itself is dangerous. A horse can spook just as easy in a dressage ring as it can in a ring full of jumps. There's nothing safe about riding horses.
In the early days of the Indian Territory, there were no such things as birth certificates. You being there was certificate enough. -Will rogers