I’ve read these sentences too... but the version I posted seems to be the most "true" one (in fact, you also wrote down that "... On the Santa Monica 1972 version, David says that it's about a 'a New York lady and a guy who lives in New York and (s)he's called The Jean Genie' ". In this sentence there's a missing 's' that I added in parentheses... Let’s leave Jean Genet aside, who doesn’t really matter except for the sound of his name).
Now, based on this version, and assuming that Bowie hated Steven Tyler (who wouldn’t?), and that he had a crush on someone who preferred Tyler over him, the lyrics now seem more than logical. Right from the beginning. Tyler was a junkie, and so was this girl. She was dependent on Tyler for the stuff he could easily get ----
(chorus) The Jean Genie lives on his back (she lived on his back. So, who lived on whose back? 1st hypothesis: the 'monkey' on Iggy’s back. 2nd hypothesis: Jeanie-Cyrinda, who was dependent on Tyler.) ---- The Jean Genie loves chimney stacks (the 'chimney stacks' are chimneys, generally of an industrial type, also present as a form in English architecture. Therefore: Jean Genie loved England. This is important. Chimney stacks is a technical term. Otherwise, just the word chimney means "wick of the lamp". For those who don’t know exactly what a chimney stack is - and what it could have to do with the lyrics - it’s simpler to assume it’s a lamp wick, etc., Aladdin, etc.) ---- In my opinion, the dilemma about the meaning of this song lies in the chorus, in these first two lines.... ----
the rest of the chorus:
He’s outrageous, he screams and he bawls (he screams and yells: could be Iggy, like Tyler, that is equally outrageous) ----
Jean Genie let yourself go! (Jean, let yourself go - that is, who? the monkey, or Jenie-Cyrinda? I think it means: Jean, come away with me to England) ----
if we continue based on the hypothesis I support, everything fits... ----
Sits like a man but he smiles like a reptile/
She loves him, she loves him but just for a short while/
She’ll scratch in the sand, won’t let go his hand