I deleted everything except:
<!-- tmpl_var message_body -->
for both the PainText and HTML message. I'd love to keep the unsubscribe and other stuff in there. But not at the cost of being repeated every time someone replies. Our threads sometimes go close to 20-30 messages deep. With most of the replies being 1 or 2 sentences. I think your template system makes a lot of sense for a news letter type list. I think breaking things down a little different for the discussion list might make better sense.
Anyway, nice piece of software, overall a great idea, thanks again,