Note that I continue to discuss MBTI ideas. I believe they are worthy of discussion and that the vocabulary is remarkably useful for discussing personal perspectives, even if the "rules" of MBTI are complete hogwash. I suspect there is a lot of (subjective) truth in those "rules," but that it can be difficult to discern.
I also suspect that the rules, assuming that they are true, are but the barest outlines of what is really going on, and that it is possible for individuals to "step outside" of the rules as understood, though such claims must be naturally met with much skepticism. Mostly, I think that if one understands that there are different patterns of thinking, and gains an understanding w/r to "how to think" in various ways, then one starts to violate the typical rules of MBTI.
My personal perspective is that MBTI describes common "equilibrium states" of the human psyche. This is balanced with that. These are balanced with those. So if one adopts an extreme posture in one regard, then a compensating posture is adopted in another area of the psyche. There are certainly imbalanced states which various investigators have tried to research (e.g., shadow functions), and I suspect that there exist human equilibria that do not technically exist in MBTI, and thus violate the "rules" of MBTI.
The main thing to recall is that if it is a subjective system, then the best one can do is share perspectives and understandings. The notion of proving others right or wrong just doesn't fly, unless such proof rests on the inconsistency of the others' ideas ... and even that is only a disproof of the other ideas, not a proof of one's own ideas.