I don’t know that there are any hard answers to your questions here…
generally speaking you are most definitely correct that you should be fueling before strength work-outs, I’m not sure the macros that should be but I believe from all I have read a fairly even macro base would be good, maybe slightly heavy on the carbs. Protein is usually considered more important afterwards (but also carbs after as well). I believe before and after you want a fairly well rounded diet with very little junk food from what I have always heard (if you’re gonna do junk food try not to do it in that re-fueling window after a hard workout.) I believe if you saw reference to intake of carbs or even calories before a session it was likely a harder training session, z3/4 or a weight training session. I could be wrong but that’s my take on it!
Regarding fasted training. I feel like a key piece of what’s missing is the zone that you are in. It really has nothing to do with time out there or even how much your pack weighs. If you have worked up to it you can do substantial time on feet in a fully fasted state. As long as I stay in z1/2 (I like to lean more on the z1 side for the really long ones) I do many 20+ mile days in the mtns after cutting off at an early dinner the night before. The key to fasted training is to work up to it and to NOT push too hard in the beginning. Sometimes for ski-mo adventures with a heavy pack I will only take calories for when the mtn gets really steep and I don’t want to go mind bogglingly slow and keep it in z1. I believe I am in a pretty good place now personally and maybe I could walk this line a little tighter (but since I’m not looking for huge gains with my training I’m just happy knowing I can go for 24+ hours at a decent pace without actually needing ANY calories. I will admit though, I have PLENTY of fat stores to pull from! 🙂
I’m not sure if that helps at all? I’m no coach by any means, just have been playing with the long fasts and long runs since it means less weight I have to carry in the mtns. And if I have to stay in z1 for training I might as well be doing it fasted (it gives me an excuse to stay in z1, cause mentally that’s really tough for me to go this slow and easy!)