Time does not permit me to rebut every one of these items, but just a few thoughts here:

Last month, in front of a roaring Sioux Falls, S.D., audience, Obama exulted: “Thank you, Sioux City. ... I said it wrong. I’ve been in Iowa for too long. I’m sorry.”

Obama said "City" instead of "Falls"-- a very understandable slip of the tongue-- and caught his mistake immediately.  I'm sure it was momentarily embarrassing, but it's hardly troubling...

In Cape Girardeau, Mo., Obama showed off his knowledge of the war in Afghanistan by homing in on a lack of translators: “We only have a certain number of them, and if they are all in Iraq, then it’s harder for us to use them in Afghanistan.” The real reason it’s “harder for us to use them” in Afghanistan: Iraqis speak Arabic or Kurdish. The Afghanis speak Pashto, Farsi, or other non-Arabic languages.

Some translators are capable in multiple languages.  And your quote is misleading in that it implies that the Kurdish language is an Arabic language, when the Kurdish language actually belongs to the same family of languages as Farsi and other Persian languages, so many translators would know both Kurdish and Farsi, for instance. 

 

Explaining last month why he was trailing Hillary Clinton in Kentucky, Obama again botched basic geography: “Sen. Clinton, I think, is much better known, coming from a nearby state of Arkansas. So it’s not surprising that she would have an advantage in some of those states in the middle.” On what map is Arkansas closer to Kentucky than Illinois?

Well, if you actually look on a map, Little Rock (where Hillary lived) is closer to the Kentucky border than Chicago (where Obama lived).  I understand his meaning here.  This is hardly a troubling "gaffe" at any rate.

Over the weekend in Oregon, Obama pleaded ignorance of the decades-old, multibillion-dollar massive Hanford nuclear-waste cleanup: “Here’s something that you will rarely hear from a politician, and that is that I’m not familiar with the Hanford, uuuuhh, site, so I don’t know exactly what’s going on there. (Applause.) Now, having said that, I promise you I’ll learn about it by the time I leave here on the ride back to the airport.”

I assume on that ride, a staffer reminded him that he’s voted on at least one defense-authorization bill that addressed the “costs, schedules, and technical issues” dealing with the nation’s most contaminated nuclear-waste site.

Bossman, I will guarantee you that no candidate ever will have a working knowledge of every single one of the thousands of line items in every appropriations bill.  If we had more politicians who would admit it when they weren't up to speed on a particular subject, who then followed thru and got the information to get up to speed on that subject-- well, that would be a good thing, not a bad thing.