Obama on a farewell tour...One last time to insult the USA...
With less than 60 days remaining in office, Obama has no business visiting with world leaders to talk about America's future direction, the only purpose of his visit is like you said, his final opportunity to bash the USA and attempt to derail any changes Trump will make. While in Greece he talked of the building "tribalism" in the United States that won the election for Trump and how much a danger it is to minorities and how he as President worked to bring everyone together while Trump will turn groups, races, religions against each other. This is the President from day one who worked hard over the last 8 years to do just that resulting in the most division our country has ever known.
Obama should not be going on this world tour to undermine America and Trump, imagine if Bush had done that to him.