Sir, I have worked in the field for many years and mostly on doing rewires and new home construction or additions to existing homes. In normal practice here in Minnesota we are normally using romex for the wiring system and all of it now is NMB so it has better ratings than the old NM. My usual practice is to wire completely using plastic boxes for inside outlets and for flush mounted outlets for the outside. If that is not possible (in doing old work or adding an outlet for outside) then a metal box is cut into the outside wall or a surface mount wp box is used. Along with the "in use cover" required on almost all outside outlets now days, we are also required to use a GFI or receptacle rated for damp locations. I sometimes try to install the GFI receptacle inside to prevent exposure of an expensive item to the weather at all. But in all cases we are to use a receptacle suited for damp locations.
The whole issue should be made plain by code experts or at least a paragraph in the code book which states once and for all if romex is ever allowed to be enclosed in pipe of any kind. There seems to be as many answers to that question as there are inspectors and code experts.