Some themes and key scenes in The Magic Mountain and three questions about Mann's novel

So many great aspects in Thomas Mann's The Magic Mountain (1924 - previous posts said 1927, but that's the date of the Engl. translation) - the strangeness and beauty of the setting; the amazing arc of characters as we watch the protagonist (Hans) grow and mature over the course of his 7-year (!) stay at the Swiss TB sanatorium; the intellectual battle for Hans's soul between the liberal humanist (Sebbetini) and the dogmatic Jesuit (Naphta) - though who can really understand what Naphta is saying or arguing?,;the fantastic array of secondary characters including the above-mentioned plus of course Frau Chauchat, Peeperkorn, and Han's cousin, Joachim; the scary inside look at the bizarre treatment of lung infection, which at times seems like it must be a scam to keep the wealthy patrons/patients addicted to the treatment at the sanatorium; a few amazing set pieces, including the death of J., Hans's clueless skiing trip during an Alpine blizzard, his confession (in French!) of his obsession w/ the beautiful and inaccessible Frau Chauchat, the seance scene - the strangest hour of Hans's life, it's said, near the conclusion, the duel, and the list could go on. Most of all, the novel is strangely allegorical, and on multiple levels: Hans's stay in the the Berghof is a retreat from an active life is a phase that most people can recognize as part of their life or of their desires - but he changes, grows, matures, and we have to wonder, is he an "Everyman"? Is his journey through life an analog for the course of all lives, for the course of history and knowledge among nations? And what about the vantage we have in looking back on his life, not only as one taking shape in the years before the First World War, but a foreshadowing of what we now know as the horrendous course of life in his native Germany in the 20th century? With all these ideas in mind, I have three unanswered and perhaps unanswerable questions. First: Did Hans ever have sex w/ Frau Chauchat? He confesses his obsession w/ her, but at the end of that passionate scene she speaks to him in the formal "vu" and tells him good-night, seeming to put him in his place. But then she reminds him to return the pencil to her (and it's her last night in the sanatorium) - is that an implied invitation to follow her to her room? (Note the sexual innuendo when she loans him the pencil; she troubles to explain to him that the pencil-led must be "screwed in" (visser) for the pencil to work. Hm. Second: Mann ends a chapter with the sudden revelation that Hans has been undergoing psychoanalysis with one of the staff physicians (who delivers to all the patients biweekly lectures on this new medical area). Why does Mann drop or lose this thread? We never see or learn anything about Hans's analysis and how this changes his behavior and self-knowledge, if at all. Finally, when late in the novel Hans sees the vision of his dead cousin Joachim during the seance, why does Hans say "Forgive me." For what? For staying in the sanatorium rather than returning the the "flat land," as his cousin did? For some unknown slight or character flaw? For making nothing - to that point - of his life?