- would Queen still be touring?
I highly doubt it.
- would there have been more albums?
- would there still be Made In Heaven?
The only reason why the album was made is that Freddie wanted them to do something.
- would there still be a Bohemian Rhapsody movie?
- would Freddie and Monserate Cabelle performed together live at the 1992 Barcelona Olympics?
- would John still have retired?
I don't doubt that. Check any late 80's interview with John, that guy wanted out.
- would Queen have returned to America? (Possibly from the success of Wayne’s World?)
- would Queen have broke up eventually?
Probably not. Bands who are not able to find new interests or hate each other break up, Queen were brilliant in avoiding that. It's possible John would retire and be replaced by another bass player.