There is real concern in some circles that if Trump loses in 2020 he wont leave, he will insist the election was rigged by the Dems etc and sue though there is not much he can do after they swear in the new president other than go to jail for trespassing...still he is conditioning his followers to not accept a loss or to think it was faked. Trump has also said many times he will be around for a 3,4,5th term, praised communist China for getting rid of presidential ( like they even really vote ) term limits, etc now some will consider this mere jokes but if Trump could figure way to try and manipulate the system to do it he would....that said I personally do not think it will be a issue when Trump loses in 2020...assuming he makes it that long.
As for the king thing there is no doubt Trump wants to be king, he thinks the government works like his businesses and he is wrong and you cant run a country that way....his entire life he has always had his ass kissed, no one ever told him he sounded stupid when he did, they never told him something was a bad idea when it was, and everyone never told him he wasn't when he said he was the smartest guy around....what you see today is a culmination of decades of that, a big dumb, idiot, who thinks he is always right when he almost never is, and who will not follow the advice of others cause they can not possibly be smarter than him. He also lies about everything......for no reason other than to do it....its almost like he believes if he says it it will become true....