OK, I've finished watching, and this may surprise you, but I honestly recommend that folks here try watching it. I absolutely would not recommend that anyone in the general public watch it, but I think a lot of people here might find it worthwhile.
Because frankly, this is the closest thing I've seen to a "Loose Change"-style attack on Obama's roots. It's *incredibly* conspiratorial, and hardly sourced at all. Gilbert doesn't merely 'ask questions'; he manufactures a wholly parallel life narrative for Obama, and does so with absolutely no factual support. If nothing else, in the midst of the regurgitated crap from the CCP, it's certainly *original* nonsense. It's also mildly racist in a way that most professional Birther efforts aren't (he actually uses the term "Jive Turkey" in part 4).
One thing to note in watching it: Gilbert will frequently show text on the screen that the narrator is quoting. Oftentimes, that's not sourced material; it's Gilbert's own 'script' for the film. But if you aren't paying close attention, the impression given is that he's quoting from some neutral source, and he's not.
And because I like to catch conspiracists crossing the line into outright and intentional dishonesty, there's a point at about 13:15 into Part 5 where Gilbert's playing part of an Obama speech, and Obama says "The free market, it doesn't work. It has never worked." That struck me as so outrageous that I had to look it up.
And I found that it's not a real quote. Despite the fact that Gilbert plays the audio of Obama saying it, and even includes some video.
Because Gilbert spliced the audio together. Obama was indeed talking about laissez-faire capitalism and trickle-down economics, but Gilbert took the words "The free market" from elsewhere in the speech, and then cut the parts together to make it sound like Obama had explicitly denounced market economics entirely. That offense alone should demonstrate the kind of 'documentarian' on display here.