I'd put more weight in your reasoning if it came from experience, which to me makes it relevant. You make claims that not sleeping on a high bed leads to poor sleep and feelings of moral superiority and yet in my experience it led to lighter sleep, not poor, and certainly I was not lying around thinking "oh those high-bedders, wasting their lives away!"
I have comparatively little experience regarding not eating after noon, but the experience I have has indeed made me more aware of just how big a part food plays in daily life, and how attached I am to fulfilling desire. Anyway, I'd like to kindly suggest that if you've never tried keeping the eight precepts then give it a try for a day, perhaps your opinion wouldn't change, or perhaps you'd see that there are indeed numerous benefits that outweigh any discomfort one may experience.
"The heart of the path is quite easy. There’s no need to explain anything at length. Let go of love and hate and let things be. That’s all that I do in my own practice." - Ajahn Chah