I agree with your first point to some extent. Psychological theories of types are helpful and useful, but only go so far. Every human being is different and has to be analysed (in the psychotherapeutic sense) differently as an individual. Jung and von Franz always insisted on this as, I assume, do other Jungians.

On your next point, it all depends on what you mean by truth, and what you understand by “how things really are”. What level of reality are we talking about? As far as I can tell, the concepts of shadow, anima/animus, Self, etc. are all psychologically real. As is the idea of puer aeternus. Dare I say that it is a fact that certain males refuse to grow up and remain in the psyche of childhood? In which case, is there any harm in calling this a puer aeternus syndrome or neurosis?

“Out of such wholeness, there is an ‘I’, a real individuality that can emerge…” That is indeed what Jung calls the Self, and is a possibility for everyone. Is there any harm in giving that concept a name?