Answer No.1
The sufferings of investigation made Galileo recant the truth he knew.

Answer No.2
The heritage being alluded is the discovered knowledge and the efforts of wise men of the past to make life on earth better.

Answer No.3
‘The betrayal of our trust implies’ that we enjoy the heritage of knowledge and works of our forefathers without doing anything new.

Answer No.4
We need to question the old truths and work for the new ones in order to make the human life on earth even more better.

Answer No.5
Inquisition – interrogation
The Planet – Earth
Falter – waver, stumble
Cynicism – pessimism
Those who are yet to be – future generations