Adolf Hitler practiced a form of vegetarianism and abstained from smoking and the consumption of alcoholic beverages. It is rumored that his favorite drink was orange juice.

Nothing in particular, but because he had a condition called meteorosis (a farting disorder), he had to be careful about eating meat and dairy. Meteorosis was probably the reason for Hitler's staunch vegetarianism.

That would be Adolf Hitler.

Adolf Hitler until his death, and then Karl Donitz.

No, Adolf Hitler is not single.