Just saw the movie... I'm stunned, this is a very good movie. Given the amazing life of Freddie Mercury, there's not so much violence and private life if you know what I mean. Not a single scene left me uncomfortable, which is usually the case in the movies nowadays. I'm a huge fan of Brian May and pretty sure the movie is so sober and good because of him.
And by the way, his character is actually the best in the movie. But actor could've learn how to play guitar for that occasion. From what I can see, seems like that they even used the original guitar on set.
I don't think that all the details are technically correct, although Live Aid performance is one of the best recreations if I ever saw. I don't think that this show was like this behind the scenes as shown on the screen. The ending of Sultans is a very good touch, although my wife missed it completely being not a hardcore MK/DS fan. So you can safely say most of the people won't even notice Sultans at all. Because she missed it knowing that you can expect something MK related.
But again, if you want a true story, go see a Documentary. This is a movie, and for a movie, it's a very good movie.