There are distinct differences between Nazi Foreign policy and the policy that a conservative nationalist government would have followed. I believe that up to 1938 Hitler was following a generally Nationalist foreign policy, then in 1938 there were key turning points, which led to his foreign policy becoming radically Nazi.
Previous to 1938 German foreign policy was mainly based on aims of the Nationalists. It is important to remember the difference in aims between the Nationalists and the Nazis, the nationalists wanted to follow a specifically revisionist policy, reversing what had been placed upon them at the treaty of Versailles regaining land in Poland avoiding war with Britain and France and in the long run wanted to make Germany re-established as the dominant force in central Europe where as Hitler wanted to unite all German speakers and use Poland as a subservient ally against the USSR (originally) to in the long run become a dominant world power.
Just before 1938 the Hossbach memorandum was clearly diverging from Conservative Nationalists policies as during the memorandum Hitler Identified his first targets to be Austria and Czechoslovakia, this is not what a Nationalist government would have wanted, there first territorial aim would have that which was lost in Poland through the treaty of Versailles. Also Hitler stated that Germany must prepare for a general European war with Britain France and the USSR, something that they specifically wanted to avoid. This is the first part of the turning point when German foreign policy becomes more openly Nazi.
The next extremely Nazi step was the purge of the foreign office by Hitler, obviously something the conservative nationalist government would not ever have done. Hitler replaced Neurath with Ribbentrop as foreign minister, Neurath had been appointed before Hitler came to power (in 1932) and was a...