His adoptive father Soetoro, though very possibly important as to his current citizenship status, has absolutely no relevance to his legal father at birth, nor to the information on his original long form BC. Although we don't know for sure, his legal father at birth was presumed to be the British (later Kenyan) citizen Barack Hussein Obama (Sr.). (In fact, an "official" Obama web site had admitted to Barack Sr.'s British citizenship at the time of Barack II's birth.) According to some legal opinions, BHO Jr. cannot be a natural born citizen if his father was not an American citizen at the time of his birth, which would appear to be the factual reality. So, pursuant to this line of argument, he would not qualify constitutionally for POTUS under such a circumstance.
As provided by law (HRS §§338-17.7, 338-20.5), the following persons may apply for an amended certificate of birth:
* A person born in the State of Hawaii who already has a birth certificate filed with the Department of Health and
1. has become legally adopted, or
2. has undergone a sex change operation, or
3. a legal determination of the nonexistence of a parent and child relationship for a person identified as a parent on the birth certificate on file has been made, or
4. previously recorded information in relation to the person’s surname and/or the father’s personal particulars has been altered pursuant to law.
* A person born in a foreign country who has been legally adopted in the State of Hawaii.
...
For a person born in a foreign country who has been legally adopted in the State of Hawaii:
* An amended birth certificate will be prepared upon receipt of a certified copy of the adoption decree or the certificate of adoption, and payment of fees."
http://hawaii.gov/health/vital-records/vital-records/newbirthcert.html
Not sure I understand your sentence regarding the BC, his stepfather and father.