Yes - the expanded version was the one I meant to link to! That was what allowed (almost) everything to fall in to place for me. Will also try to reintroduce my brain to the notion of flexibility, and will follow your guidelines when I get brain-seize again. I may have to introduce a cerebral .htaccess to rewrite 'include' as 'super-include' or 'plug-in'. (My RewriteEngine is increasingly off by default).
Thanks Ray, having read the expanded pdf, I bought the extension. I had already largely understood from Russell's pdf the benefits, but the possibilities (using the various triggers in various template scenarios) are still dawning on me, the whole now appearing to be considerably larger than the sum of its parts, and my imagination now running a little wild.
Can't emphasise enough the benefits of visual detailing to people such as I.