Well, there is the one minor detail of Obama Sr. being a citizen of Kenya, which automatically disqualifies Obama to hold the office of President, per Article II, Section I of the US Constitution.
Also, per the citizenship laws on the books at the time of Obama's birth, his mother would have had to have been a resident of the US for ten years, five of which were after the age of 14. Stanley Ann Dunham was 18 at the time of Obama's birth, so per the law, she was not legally able to convey even simple US citizenship to her son, much less Natural Born citizenship.
I couldnt find anything that existed beyond conjecture.
Funny how you missed these two major points of fact while you were doing all of your research. You have to actually look, in order to find.
There is no part of Article II, Section 1 that says that a person is not natural born if one parent is a foriegner. To top it all off - We've had a president before with a foreign father - Chester Arthur.
Your second point - the mother had to be a citizen at least 10 years - doesn't even make sense. She was a natural born citizen by any definition - that isn't up for debate, is it? Probably, though, I am just not understanding your point. What law are you specifically citing?
Just to keep things moving along - this is what the current state of the law is vis-a-vis Natural Born Citizen, taking into account the constituion and such: http://www.usconstitution.net/consttop_citi.html