ST, the POH point has been gracefully acknowledged and I'm not going to labour it since, as I noted elsewhere, I actually believe that judgements are always needed and go hand-in-hand with an understanding of the POH.
I quite understand your resolution to keep up standards and the need to draw the line. It put me in mind of a piece by Garrison Keillor who linked the installation of airconditoning to coming home and finding one's mother in moral turpitude
I don't see myself needing to lean routinely while applying carb heat but, while there was no carb ice involved in the wasp incident I mentioned, experiences like that one underline that information sharing is useful in opening our minds to possibilities which may help in unusual circumstances. But I would just comment that an inexperienced pilot managing to stop the engine while in a confused state will certainly change the flying quality of the aircraft.
It's interesting that there is a new generation of LSA aircraft powered by Rotax (and other) engines in which there is no carb heat installation. A common view is that the position of the air intake source and the nature of the carbs mitigate against icing. I'm sure this is largely true but it was sobering for me when I did once clear some ice on run-up (being a certified variant of an LSA, my aircraft has a conventional carb heat arrangement). I have no way of knowing if this would have been a problem at full power (and maximum engine environment heating) but I'm not sure I wanted to find out. Of course, it could be that making the air induction system more 'conventional' for certification has negated some of the advantages of LSA installations.