I'll start this with the disclaimer that behavior is not my strongest area of vet medicine. I've had most of my personal experience with Golden Retrievers a breed so easy to train that it's hard to screw them up. After spending hours every day dealing with difficult behavior (almost always understandable as the things we do are often uncomfortable or strange), the last thing I want is to come home to more difficult behavioral situations.
Most animal behaviorists do not recommend pronged collars. Many trainers do. I don't think there is a universal situation (always OK vs never OK)- each individual situation is different. The behaviorists maintain that pronged collars are used by owners as an easy out rather than dealing with the bad behavior.
There are tons of new training aids as far as collars, harnesses, head collars, and training protocols. Many current behaviorists also discount the "alpha" dog theory that we all grew up with.
Bottom line is that dealing with an adolescent dog can be difficult. You have to be willing to try different things and even change things up when what has been working no longer does. Far too often people just tire and give up and that produces an adult dog with poor behavior. We've all seen them, those that bark uncontrollably, lunge while walking, are aggressive to people or other animals and any number of other undesirable behaviors.
One universal theory is that a tired dog (both physical and mental) is a good dog. Uniform, regular daily training on a schedule (feeding, elimination, play, exercise and training) seems to have benefits. Don't ignore the mental stimulation as a bored dog will misbehave.
The fact that you are seeking suggestions means that you are actively dealing with the situation. Keep the faith and keep trying different things. They do grow up.