1. Both have a system of voting to decide major issues like whether or not to go to war. The difference is in who can vote. Mostly it was an issue of property in Athens. You had to own property to be able to vote. Foreigners and women were not given the vote.
2. It was a citizen's duty to debate the issues in Athens. America, when I was growing up, had a similar stance. I believe it is more repressive now.
3. The vote, once completed, was what was done. That idea in America ended with Gore vs Bush over the Florida election. And now all that can be debated is Trump. I'm not fond of the man, but I also don't like the fact that people are "at war" about whether or not he should stay in office. The cry is for impeachment, especially from some democrats. There is little hint of cooperation in that. Before all this, though once elected, a president (with the exception of Nixon) could look forward to a modicum of cooperation.
It would be "executive privilege" that describes a President's need to keep information private, since this can allow the President to keep information from both Congress and the public.
