Short answers, pulled from the story.
Queen played their first show with the classic lineup on the 2nd of July 1971 at a Surrey college outside London. This performance featured Freddie Mercury, Brian May, Roger Taylor, and John Deacon together for the first time.
A Night at the Opera cost £40,000 to produce making it the most expensive album ever created at the time. The project utilized three different studios and included diverse musical styles including fantasy-themed lyrics.
EMI initially refused to release the single thinking it too long but Capital London radio DJ Kenny Everett played the promotional copy fourteen times over a single weekend. Capital's switchboard was overwhelmed with callers inquiring when the song would be released forcing EMI to release it due to public demand.
The sold-out stadium audience numbered 72,000 people who clapped sang and swayed in unison during Queen's set at Wembley. Organizers Bob Geldof and Midge Ure described Queen as the highlight alongside other musicians like Elton John and Cliff Richard while journalists writing for BBC CNN Rolling Stone MTV The Guardian and The Daily Telegraph all praised the performance.
On the 23rd of November 1991 Mercury confirmed that he had AIDS in a prepared statement made on his deathbed. Within 24 hours of the statement he died of bronchial pneumonia brought on as a complication of the disease.