No country is referred to as 'The Heaven of Europe'.
Italy
Norse in not a country, but referred to the north of Europe, or Scandavavia. The countries are Norway, Denmark, and Sweden.
Germany
That's not a complete sentence. Barring that, the answer to your intended question is France.
The reference was to Italy .
Hungary. The Netherlands is also sometimes referred to as 'Holland'
The Workshop of Europe (and the world) was a nickname given to the United Kingdom. Its capital is London.
Detroit is the Motor City.
powder keg of Europe
It would have been considered to have been an east European country.
The Balkan Peninsula.The Balkans were referred to as the Power Keg of Europe.