a) Eric I. Duke of Mecklenburg was the son of the King of Sweden.
b) Eric II. Duke of Mecklenburg, was the fruit of the marriage merger with the house of Pomerania, which in turn led to links with other european royal bloodlines - link
6) I'm thinking that "Eric Schwerin" may be an alias, in much the same way as the Prince of Wales (Charles Philip Arthur George Windsor) might sign in to a hotel as Arthur Windsor. If so he could be a member of the royal families of either Sweden or the Netherlands?
7) Consider also the Czechoslovakian students Eric taught - Czechoslovakia is the country that land-links Germany and UKRAINE!
8) The coat of Arms of the House of Mecklenburg-Schwerin has the symbolism of Baal, Dragon, Adrenochrome and BLOOD RINGS: