In general, I think politicians are difficult to read. They tend to change their message depending on their audience and tend to talk very vaguely about topics to give themselves wiggle room. Their views can shift as quickly as the wind and they often seem to put a priority on getting and keeping their jobs over conveying their true opinions.
Trump is the politician that is the most difficult to read, at least in my lifetime. I don't think he writes speeches and even if he uses a teleprompter, he rarely follows it. He just says things; whatever comes to mind that sounds good in the moment. He'll say one thing now and say the opposite in 5 minutes.
Another reason why I don't see him as a serious threat to the country is because, yes, I probably have more faith in our system and the people running it than a lot of Democrats do. I saw research years ago that showed that one of the big differences between Republicans and Democrats was risk tolerance. When it comes to Trump, the risk seen by Democrats is so vivid and realistic that it's almost like it's already happening.