I don't think the name change by itself means much. Legally, you might have trouble with your perjury argument or with the proposition that the name alone means much as long as it wasn't being used by A to deceive people into thinking he was B. Reason people spend money and go through these elaborate proceedings from a legal point of view to change names is to be sure that their name representation to the credit card company and the bank and the IRS and their employer with their SS card is acceptable and to get a Court Order which can be used by itself to line up all the identification documents on the same name.
Fact he is still an Indonesian citizen is substantive. And his Indonesian citizenship and subjection to Indonesian sovereignty ought to preclude him from being a Natural Born Citizen, even if he were born in Hawaii (he wasn't).
However, I would not be surprised (although this is out and out speculation) to find that what he did at some point was do a State Department proceeding to reclaim his citizenship under the statute that permits children to disaffirm acts of their parents surrendering citizenship.
That would have been the easiest proceeding to hide; and would have produced documents he could have used to get a passport. And might very well, as you suggest, have resulted in a filing with Hawaii that would have generated him some form of fake birth certificate.
Since in 1980 thru 1982, it is not even remotely likely that Barry Soetoro foresaw being a Seantor from Illinois or a presidential candidate, it is likely that he used his Indonesian citizenship as an adult to game the college netry and perhaps college tuition/scholarship programs, and to travel on an Indonesian passport. THAT constitutes a default to Indonesian citizenship as an adult. Any subsequent act to regain sloely American citizenship would constitute citizenship via statute and make him precisely ineligible for the primaries, much less the swearing in.
Frankly, the more one considers the logical conclusions, the more it appears Fukino was lying through her teeth for her affirmative action liar-in-chief! Of course, we should not expect Linda Lingle to seek to get to the truth since she has already acquiesed to the pressures from the DNC machine. I wonder what juicy crap is in her FBI file held in the White HOuse? There doesn't appear to be a true patriot int he entire political arena. And frankly, Dick Cheney's obsequious disattention at the moment he knew he had to act to save the Constitutional contract is disgusting and the real historical perspective on the man. In the end, he too was nothing but a two-bit politician playing the political games, Constitution and We The People be damned for the little nuisances the poli-class sees U.S.
But, if he was an Indonesian citizen and used that citizenship as a teen and young adult, could he reclaim his American citizenship without being naturalized? These are important issues that need to be resolved.
No, once natural born, no actions taken by ones parents, natural or adoptive, can change that status. It's even true citizen children in general. Only he could have renounced his citizenship, and even then not until he turned 21, in general anyway. Of course if had done that, there would be paperwork.