German
Wilhelm Wundt (1832-1920) was the first person to call himself a psychologist. In 1879, he founded one of the first psychological laboratories in Leipzig, Germany.
'Hamburg' is a city in Germany. In English, one could call a person in or from Hamburg a "Hamburger" (capitalized).
We call it "weihnachten"
Yes, both "Deutschland" and "Germany" refer to the same country in Europe. "Deutschland" is the German word for the country, while "Germany" is the English name for the nation.
The Romans called Germany, "Germania".
Germany's got talent
Santa is called der Weihnachtsmann in Germany.
A person who was born in Germany, or was raised in Germany but later migrated, would be a native German. This would be the person's ethnicity.
Deutschland
whatchamacallit
deutschland