Not true. The 14th covers folks born here not of diplomat parents. However, others born abroad to US citizen(s) are also Natural Born. E.g., John McCain, whose estimable service to the Republic should have ended decades ago.
No way. The only thing that might make McCain a NBC is if he was born in a US territory, and that is iffy.
If you think McCain could have been born anywhere and still been a natural born US citizen, then you got to believe that someone can be a natural born citizen of multiple nations. That would be a mockery of our Constitution.