Spot, if what you've been doing is working for you, then obviously you're doing it right. Not all of us are blessed with the kind of untutored voices or the innately and automatically good technique that can make us sound as good as we can for as long as we can without damage. Good for your choirmaster--(s)he probably taught you right. OTOH, I have seen more choir directors ruin more solo voices by forcibly suppressing natural vibrato and having singers do "warmups" that really should not be done without more gradual warmup exercises preceding them. One thing that drives me nuts is uncertified people trying to teach singing--and by "certified" I do not mean any one particular method of pedagogy or certifying authority. To me, someone without formal voice pedagogy (not just voice) training of some sort (either conventional, conservatory, or one of the newer programs) holding him or herself out as a voice teacher raises HUGE red flags. Anyone looking for a teacher should check out their prospective instructor's formal training and professional affiliations--membership in the National Association of Teachers of Singing (which has a wide umbrella of styles and methods among its membership) is a good sign.
And the "tight throat" singers of the British Isles and high lonesome bluegrass styles who haven't hurt their voices probably don't sing that way every day for hours on end, so that's why they haven't evidenced any vocal damage. Many, if not most, are probably amateurs or semi-pros (and I use the term quantitatively, not qualitatively) who just don't sing that long or that often.
I am NOT a voice teacher--I teach only guitar and dulcimer. I am merely dedicated to making sure people don't wreck their voices studying with people who have no business holding themselves out as teachers. (And it's no surprise that Riggs is losing adherents faster than George Bush is losing supporters on all sides--ever hear the guy talk? Any voice teacher who smokes as much as he has--or had--is IMMEDIATELY suspect in my book).