Did President Roosevelt consider American public opinion when deciding how to respond to the conflict in Europe?

Absolutely he
did.  Roosevelt wasn't elected four separate times for no reason.  He was a fantastic politician
who knew that the American people were mired in the Great Depression, and in no mood to become
involved in what they viewed as "Europe's War".  This is a sentiment known as
isolationism.

While FDR was well aware it was not politically possible for
the US to enter the war, he also knew that he had to do something to help out the Allies, who
were losing badly in 1939-40.  So take Cash and Carry policy as an example of his bending to the
isolationism of the time - all weapons sold to Britain had to be paid for in cash, and carried
on British ships, so it would not appear to either Germany or war-reluctant Americans that we
were entering the fight.