^^^ You have touched all the major issues, sadly there is a lot more. There are only three sources that we can trust to give a clear picture. Interviews of Yulia, Eteri, and Averbuckh (plus Alexei and Zueva in the past). Yulia for facts, Eteri and Averbukh for attitudes and atmosphere but not facts. If one really wants to understand Yulia, stop right there.
At the top of my list of things to check is the pejorative use of the term introvert. Yulia devoted herself to skating from age 4. What do we expect her to talk about at a dinner party? Social isolation is common among top artists, for example top classical pianists know everything about their repertory, but typically little else. Yulia lamented the departure of her dear friends who always went away, beginning with Shelepen. Other top skaters have the same complaints about active friendships, are they all introverts? Her distrust of strangers is normal given the treatment she has received. Not wanting to be in the public eye is not introversion, and I can't find a thing wrong with wanting to spend some time alone with a book. Would we prefer her to be glib and superficial? Introversion is not a mental disorder, each of us has a level we are comfortable with that should be respected. It's past time we show some respect and drop this one.