To the best of my knowledge that doesn't matter.Once you're established as a US citizen it's *very* hard to have that status revoked involuntarily.I could explain why but it's a long explanation and my two fingers are tired! ;-)
Not according to the law in effect at the time he was born.
That could very well matter.I think I've read that there have been periods where,under the laws in effect at those times,if you were born during them...under certain circumstances...you did not gain US citizenship at birth.I thin k I read that 1961 falls into one of those periods.So,it's *very* possible that Osama's refusal to open his records is because he has something,Constitutionally speaking,to hide.Something big.
The laws have been gone over here thoroughly, there is no such circumstance in 1961 unless his mother was sent to Kenya to give birth and sent back within a few weeks.