How could an early grade school age kid change his citizenship?
You’re right that little kids can’t change citizenship on their own, but due to marriage, and some other circumstances, people can be handed citizenship. I was, when I married someone from another country. I didn’t ask for it. Probably the important Mr Soetoro could just go with the right denomination of bills, or maybe not even, and get his son Barack a passport.
“...somehow mama Stanley Ann got her baby onto her own passport to get him to Indonesia. ...”
And that gives rise to this question:
What documentation did a mom need to provide back in 1965-1966 in order to put a kid on her passport?
Recall that in the 1968 passport renewal app, she lined out both “Barack Obama” & “Soebarkah” after trying to add “Barack Obama” & remove “Soebarkah”... so, yes, 0 was on her passport at some point....