The clip was taken out of context. An alt-right activist posted it on Facebook, leaving out the important parts that followed. In the clip that's included, he is explaining why Trump supporters are rightfully angry, and then in the part that is excluded, he explains that they will regret their decision soon after Trump is elected, because he won't actually do anything to help them.
In the audio clip Michael Moore explains why he thinks people in certain states will vote for Trump. He then goes on to liken this to the Brits voting for Brexit and explains how, like the Brits post-Brexit, many of these American voters will quickly come to regret their choice. This is not an endorsement of Trump.
He really hates Hillary. It is surprising to many people who are his fans that a liberal who does not believe in guns would endorse Trump, but he did. He was very clear about his reasons why, and he has made it clear that he thinks Trump would be a better President.
No, I do not believe that Michael Moore's endorsement of Trump was taken out of context. Michael Moore was known as a Hillary supporter but he has also taken the time to take a good look at what this country needs to be successful in the future. He was able to put his personal thoughts aside and see that Trump actually is a change for great change in America.