Having read and listened to much of that, where I come out is that I don't want to "understand" Islam any more than I want to "understand" cannibalism. I don't buy into the notion that only if we understood the Muslim religion better, we would be able to live side by side better. And the more I understand about it, the less I am inclined to view anything about it favorably.
The fact that Sunni and Shia groups split in 7th century over next to nothing is no more an "explanation" or a justification for car bombs exploding in Baghdad than is whatever happened in history between Serbs and Croats a reasonable grounds for them slaughtering each other centuries later. And the same goes for Hutus and Tutsis or lately Fatah and Hamas.
We don't need to "understand" Buddhism in order to not have Buddhist monks detonating themselves in a coffee shop next to us.
Muslims and Islamic nations have to earn the right of being part of the international community just like everybody else and that includes acceptable behavior towards those who do not share the same beliefs. Those are the rules and everyone has to abide by them and making exceptions can only lead to a bigger disaster.
If that fundamental acceptance does not exist, it should be firmly enforced.