I think "who cares?" is a perfectly appropriate response to the "is it folk?" question. Like Bartholemew, I enjoy these discussions (somewhat), but reject the dogmatic approach espoused by those who think that there is only one acceptable definition of "folk" -- their own.

Thomas, I feel that you should write because you want to or are driven to. In my opinion, writing for "posterity" or to "continue the tradition" is a mistake; you're not likely to hit the mark, and having this as your objective will only stifle your creativity. Once the song is written, it will live or die on its own merits, categories be damned. The folk process works best when we're not too self-conscious about it.

As for encouragement, when I write it's always the song that encourages me. I try not to look to others for rewards that should come from within.