We cant start making up new rules to fit our desired outcome. Either the citizenship is pure or it is not. Obama is not, and I don't give a crap how or when he gained all the extra citizenships, five years old or forty, renounced or otherwise, based on law passed 100 years after the constitution was written.
Twisting this shit into a pretzel is getting ridiculous, and this is why born of two citizens is the only correct answer. It leaves no room for foreign influence.