Well concerning situation in East Europe. By 1570 an interesting situation may have arisen here.
1) The deluge will make Livonia surrender to the troops of Moscovian czar Ivan IV The Terrible thus strengthening his position on the Baltic coast, and this may make Lithuania be tractable with the Czardom of Moscow concerning the lands of Polotsk.
2) Please, remember that flooded lands of Northern Germany will make protestants who mostly populate them seek shelter in catholic lands or in Sweden. Lutheranism on the continent will suffer huge defeat. These people, however, may flee to Poland where in this very period protestantism is very strong. In 1572 King Sigizmund of Poland dies (the last of Jagellon dynasty). Henry (III) of France is not a favourite challenger for the throne of Poland. Now the fight is between two giants: the son of Emperor of Holy Roman Empire and Theodor, the son of Ivan IV The Terrible. In actual history, Henry of France won the election because Polish nobility wanted a Catholic king but here France is weakened, Lithanian part of the Sejm (Parliament) wants the orthodoxal king who would be of the same faith with them, part of Polish nobility is in hesitation because Poland is "infected" by protestantism very strongly, moreover, having access to Baltic trade routs, Ivan IV has now gold to "buy" votes. So, here his son Theodor may be elected as the king of Poland. Ivan may go farther and, himself, conclude marriage with Elisabeth of England thus securing sea trade in Baltic and North Seas. England desperately needs resources of Moscovia, Moscovia desperately needs English naval and metallurgic technologies. How Anglo-Moscovian Union may affect further history of Europe?
All depicted above is not a fiction at all, these trends existed in Actual History but have never been realised. The deluge may put them on top.