i think it must be the same case of the montreux rose festival
the organizers of that gig wanted the bands not to play live
so, for example, freddie had to do lipsync, and so all the rest of the band
(if you look very carefully, freddie wanted the people to realize he was lipsyncking (he sang without the mic, etc)
the response to that question it's on the Freddie Mercury Video Collection (video interviews with the directors of the videos) and on the 2DVD set of Lover Of Life Singer Of Song (audio commentary to the videos)
no
i don't have the DVD with me, but i think that they were going to play all songs live
but i think that was the show promoter/organization that advised to NOT to play the songs live