"the Civil War shouldn't have happened" - every other liberal democracy was able to end slavery without a civil war, the civil war wasn't about slavery so much as about centralization of power
"privatize the [FAA]" - if we didn't have monolithic Secur Ity policies, some AirLine passengers might have had guns, and the World Trade Center attack wouldn't have succeeded. (He may have a general point about the [FAA], but I don't think I want guns on planes, except in the cockpit and in other Profession Al hands - although I'm not even sure I trust the latter since it may not really scale to the number of flights that happen.)
"eliminate the CIA" - Maher said "in Dealing With Terrorism, even if they're a little crazy, don't we want them on our side", and Paul responded "you might feel better, but you're less secure - if the CIA hadn't put a puppet government into IRaq in the first place, we wouldn't be dealing with this".