Your facetious claim, “First, it is false that Obama’s birthplace is unknown. It is known based on exactly as much documentation as exists for all but at most 8 of the other President on that list.”, is just plain silly.
“Of 43 men who have served as president, only Zachary Taylor and Andrew Jackson, both born on the frontier, have disputed birth sites. All others have some commemoration for their place of birth except Obama.” from:
http://www.newsmax.com/Ruddy/Obama-birth-certificate/2009/12/12/id/341849
There are other ways of verifying where a person was born other than providing their long form birth certificate. Unfortunately, unlike the other presidents Obama has been unwilling or unable to provide verifiable information about his birth or even the location of his birth. No, Obama’s COLB does not provide verifiable information. If you think it does, please explain.
If you know where Obama was born, why don't you tell the rest of us? If you can't tell us the hospital or address where he was born then you don't know. Two different hospitals have been claimed by Obama or his representatives or family members. First it was claimed that Obama was born at The Queen's Medical Center. Then for six months Kapi’olani Medical Center for Women and Children claimed that he was born there. then they mysteriously dropped the claim
http://www.wnd.com/?pageId=103633
http://www.earthfrisk.com/blog/?p=135
Then you go onto claim that persons who believe Obama should provide the documentation of his life are a “fringe group of conspiracy theorists who would never vote for him anyway.”
I guess that you haven't looked over too many of the polls on this. From Polls this summer, “Tom Jensen of Public Policy Polling just reported on Twitter that a new poll his firm conducted finds that only 32% of Virginia Republicans think Obama was born in the US, while 41% think he was not and 27% are not sure. These numbers are even worse than the national results from the Daily Kos/Research 2000 poll released on Friday, which found that 28% of Republicans think Obama is not a citizen and 30% are not sure.”
http://www.brendan-nyhan.com/blog/2009/08/va-poll-backs-kos-result-on-obama-birth.html
That doesn't sound like a fringe group to me. The numbers have only gotten worse since that time; I just do not have time to list all of the links.