For point 4, I’ve got a post you mind find helpful
Ultimately, the famine is about priming the body FOR the feast. You get the body into a state where it becomes VERY efficient at wringing out every last drop of nutrition from what it eats, and then you BLAST it with nutrition so it completely maximizes it. And after enough time feasting, you don’t want that response to become blunt, so you famine to get the body unsettled and ready to resume that.
It’s the same with my weekly nutrition: I’m constantly varying food intake levels to keep my body guessing.