I wouldn’t be totally surprised if he resigned after four years due to boredom. Anything is possible, but I expect him to serve the full term.
The latter is absolutely 100% going to happen. Trump is extremely pliable. During the campaign I read several times that he takes on the views of whoever spoke to him last. So long as they flatter him they’ll be able to whisper just about anything in his ear and see him say it and do it.
His presidential library will consist of a dozen coloring books.
The only thing that could stop him doing the full term is maybe health. I could see him blowing a blood vessel somewhere along the way.
I’m voting heart attack while grooming his potential (fourth) wife during a moment of panic when he realizes his current (third) wife is still in the building.