UB Ed..if you list 27 different things that 'seem' to be charactertics of folk songs (songs almost EVERYONE agrees are folk), being played acoustically is one. Certain rhythms are another. Im my not-so-humble *grin* opinion, I wouldn't call a song folk until it had a preponderance of the 27(or 14..or 58) characteristics...and preferably more than ¾ or so. (No real dividing line for me, and NOT being folk does NOT mean I can't like it, I just would say that THIS song I like is pop, or Bluegrass...or whatever)

So...my answer is, no, I don't think your Arrowsmith example makes it 'folk', as changing only a couple things don't change the 'basics'...doesn't mean it's a bad thing to do, or that you should change anything you sing....just means that if you get famous and record it, I have an opinion about where it should be located in the music store.

As you have seen, my opinions are not necessarily shared by everyone.