What you failed to include is those acts must be performed as an adult. A minor child cannot relinquish U.S. citizenship and they cannot have it relinquished by someone on their behalf.
Also, had Obama been adopted by Soetoro then under the Indonesian law in effect at that time he was most likely too old to have Indonesian citizenship granted to him. He would have had to apply for naturalization when he became an adult. By that time he'd been living in the U.S. again for years.
A minor child cannot relinquish U.S. citizenship and they cannot have it relinquished by someone on their behalf.Not true. You're confusing a situation where a minor is still living in the U.S.A with a minor who has permanently moved to a country outside of the U.S.A. It's xenophobic to assume a U.S. citizen would never renounce their citizenship to become a citizen of the country they are living in. Minors have as much right to pursue citizenship outside of the U.S. as an adult.