The problem with Huckabee being a Florida resident is that if he runs with one of the Florida residents (I refer to Rubio and Bush – Scott isn’t well liked in FL), the Florida electors would not be allowed to vote for both of them, as per the Constitution.
In regards to answer 3, my reasoning was sort of like your postscript – Petraeus is electable.
In regards to answer 2, the difference between Reagan’s era and now is that it was then a Cold War, not a physical one.