People are not being born as baritons and tenors. I am a baritone and I think that Freddie's voice was set around 1 tone higher. He had a good range which let him sing high notes, but he's certainly not a tenor. Roger Taylor is a tenor and Roger Hodgson (maybe the best example) is a tenor. Also James Dean Bradfield off Manic Street Preachers is a tenor, although a little bit"lower" than Hodgson. If You listen to them: http://www.youtube.com/watch?v=aZNMlbHwnEY http://www.youtube.com/watch?v=DlKNVkU3DTA
Freddie wouldn't be able to sing A Design For Life live.
The other important thing is that one can use hus voice million ways and Freddie chose what he chose.
He was also a great live singer although he had worse nights and worse tours (magic tour, live killers tour, lotta Japan gigs) but as M. Caballe said he had been selling his voice. The Earl's Court's Death On Two Legs is a great performance, who cares for a vocal crack? He would have been sung better if he just stood and conctrated to sing, that's for sure, but this is not what it was about.
And comparisons? Bono was a great singer in 80s, that's for sure, but he's not anymore. Robert Plant was very weak, he really had more bad performances than good ones, but still he was a good performer. And Immigrant Song? Common, it was just fun and did anyone hear a good quality recording of it? How do You think Plant sings March Of The Black Queen?