“Also indicating the passage was DICTUM.”
The DICTUM in the quoted Minor court language concerned only the question of citizenship of the children born to aliens and foreigner...which was explicitly NOT reached.
IMO the NBC language in Minor was NOT DICTUM but was a “HOLDING” declaring that born in the country of parents who were citizens are NBC. Only a subsequent SCOTUS ruling will affirm or deny application to the facts regarding Obama (whatever the heck they are!).
NBC definition has nothing to do with the case.
What is Obiter Dictum? See Black’s Law Dictionary or cases discussing the definition.
http://blackslawdictionary.org/dictum/
You are correct. The Court held that Minor was a citizen before the 14th amendment precisely because she was born in the country to citizen parents. Their discussion of NBC was absolutely a basis for their holding. The Court did not decide anything about other types of citizens because it was not a question put before the Court.