at the end of the day, in most cases, the most dangerous person isn't trump, it's the people he is surrounding himself with
I truly believe that donald trump is still, on like 75% of issues, a largely apolitical person. but he recognizes that the right is fractured between moderates, tea partiers, and the alt-right, and so he's trying desperately to appeal to each of them in turn.
the problem is, while he might be wholly insincere, this will lead to people like John Bolton, Stephen Hadley, Jose Rodriguez, Myron Ebell and Jeff Sessions likely having power in his cabinet, not to mention Steve Bannon. because we have such a cult of personality around presidents (especially when they run on exactly that logic like a trump does), we often ignore the power that such individuals have.
in the first term of the bush administration, as we now know, almost all of the foreign policy blunders committed (the domestic stuff would've happened regardless) was due to a fairly small group of bush's inner circle- cheney, rumsfeld, wolfowitz, ashcroft/gonzalez, etc. it's likely we end up in a similar situation, only with even fewer moderate figures (colin powell, richard armitage, paul o'neill etc.) to push back