"Certain knowledge should be suppressed for good of majority." Given that Bradbury lived in 21 century, what is the theme or message of the...

I can only answer one of the two questions presented, so I
will address whether or not the quote provided is a theme of the
story.

Knowing Bradbury's work as I do, I cannot imagine
that he would ever suggest that any knowledge should be suppressed.
I believe that he would expect people to be exposed to all knowledge and be allowed to
decide for themselves how best to use it. (This is a theme in Bradbury's novel
Fahrenheit 451.)

Knowledge comes with
responsibility. Bradbury seems to recognize this, but also believes that people should
be given free will to make their own decisions, and learn by their mistakes if
necessary.

I don't believe that the theme of "The Flying
Machine" is that "...certain knowledge should be suppressed for the good of the
majority." No one should police one's thoughts or beliefs. If this were ever the case,
who would "police" the police? I believe that Bradbury portrays the Emperor as a leader
with limited vision and unrealistic expectations of his ability to control the world
around him. I do not believe that Bradbury supports the Emperor's
actions or philosophy, as it is stated in the quotation above.