What Trump says today about Ryan won't matter. Ryan will either be reelected or defeated six days from now. Hopefully he will lose because he would be one of the biggest obstacles to a President Trump's following through on the issues that would have won the presidency for him.
Ryan, in his backhanded way, has been trying to damage Trump for several months now and Trump should not endorse him. Remember:
Trump is the Republican nominee.
Ryan is still in his Republican primary with a primary opponent. Big difference and the same goes for Juan McCain.
Trump nor any other Republican is required to endorse anyone in their primary contests.
Maybe, but I don't see how alienating the party helps get him elected. We'll see.