There is actually a lot of therapy that has been incredibly well studied. And you know what they have found? The #1 predictor of whether therapy is successful is the relationship between the client and the therapist. So nothing else matters as much as that. Your mistrust is in the small things, when in reality, it's your relationship with your therapist that will be the most beneficial aspect of therapy. Do a little Googling on therapy and therapy methods and you will find which ones are more studied and which are less. It's not an exact science, but as a fellow INTJ, I have learned enough to know it is a science (more along the lines of meteorology than physics).