#5 is a direct quote of General Mattis.
Since the USMC has the same handgun as everyone else, #6 is just silly. They had the M9 forever, only MARSOC went back to the .45 and now, they’re back to the M18 along with the rest of the military and the rest of the USMC.
This whole thing has an apocryphal feel to it, though there are some good thoughts contained within.
But I sincerely doubt that there is an official origin to this collection.