I stumbled into this section by accident, I have a 2014, and clicked on this thread when I saw it. I found some of the comments interesting because my car seems to be showing similar symptoms. I thought it odd that it was limited to the hood. I will have to search for some of the other threads mentioned. I called Ford about it thinking there might be some coverage with the 5 yr, unlimited mileage corrosion warranty but it oddly doesn't cover rust, only perforated metal. No hole, no coverage.
On the surface (no pun intended) it sounds like the nature of the beast