Prussia was the state and former kingdom of Germany. Austria became a vassal state to Prussia. Later on Austria and Prussia become little more than just vassal state.

Prussia replaced Austria as the leading German state by promoting customs free trade with neighboring states. There was also a demographic shift from Germans to Slavs and Hungarians in Austria.

Yes Maria Theresa made Prussia military state .

Prussia was not absorbed into the German state, the state of Prussia founded the North German Confederation which then became the German Empire with Prussia as it most important state, the King of Prussia became on the inception of the country of Germany, the King of Germany or the Kaiser. The Kaiser's were the Kings of Germany until nearly the end of World War 1 when Germany became the Weimar Republic, which was then taken over by election by the Nazi Party and then became a dictatorship under Hitler and Nazi Germany.

Prussia.....=D Prussia.....=D