I agree there is a certain % that just do it all wrong, you can see a whole lot of newbies ATM who just want everything now and that is a recipe for disaster, your head can get it all, but it takes a while for your body to adapt and change modes, I think most individuals have some degree of metabolic damage that needs to be rectified before VLC.
Liver, kidneys, and the rest, there are likely numerous things that need to be rectified.
Leptin works in many different areas and also in concert with other hormones, so again, just because you felt your hunger signals were fine does not rule out Leptin resistance.
Adrenals may well have been affected, but I see the adrenals much the same as thyroid, they are acting in response to other underlying problems and yes they may well get fatigued through overuse and may need specific care, but the underlying issues need to be addressed. Downregulated adrenal receptors, could also be termed adrenal resistance, just a case of overuse possibly, I don't believe adrenalin is always required to release fatty acids, just in emergency situations the adrenalin is like a turbo to boost supply temporarily, and it may well be if your normal systems FFA release systems are down, then your body reverts to the Adrenals just to get through and if extended over a period this would result in Adrenal fatigue. Thanks for sharing your experience, adds plenty more to my considerations.
Personally I think it would be better for nearly everyone to just do a good 12 months straight Primal/Paleo before they consider IF or Ketosis, fine if you just drift into it, but if you are forcing it there is something wrong with that in my eyes.