Hi Wolf, great thread. I am very passionate about your point C.
Just Jeff and Peter Pan , multifunction is a key element and after playing with the JRB Stealth I am now waiting for the "Down to Earth" (my name for it) No Sniveler and pad combination.
Highway, not having done a "trough hike" (yet) I can only comment on multidays walks, and you are spot on. I would suggest one or two extra "energy" bars , someone posted a recipe for a home made version that results in a 1000 calories bar +/- ( I am sorry but I cannot remember where I got that from) I made my own and eight months later the remaining one tasted as fresh as the day it was made ( lots of different nuts,dates,honey,olive oil,sesame seeds, protein). Just one bar will be a good meal substitute.
The cold water bit, yes it does make a difference, just look at any fuel efficiency tests.
In a similar way, if you use standard "dry" food not the "freeze dried" it helps if you add some water to it as you hike ( put your dinner veggies and meat with about half of the water required, usually half of the volume, in a Lexan container after lunch and add the other half at dinner, the boil time required will be a lot less).
A hot cap before going to bed, for example hot chocolate made with the normally drained water from veggies/pasta (use full cream milk powder) will give you a good start and avoid the need to have extra clothing with the often resulting cycle of sweating /shivering ( you sweat,soak your base layer and bag and then get cold from the resulting evaporation)
Franco