For me Trump's biggest problem is that it looks like he is Putin's doll. Even if he isn't that just look like it and he would probably be outplayed by Putin and give him anything he wants which in the long term is not good for US. Russians and their KGB are master manipulators and current information war really proves it. It went as far as "Hillary is eating children". Trump's megalomaniac personality might make him not to listen to his more experienced advisers and bad decisions might be made. That's what scares me. Having said that Thiel is a smart man. Trump is also a smart man and he could be a good governor or senator, but it's too early for him to take charge of the biggest and most powerful country in the world.