First off, wow. And congrats! Chris is the real expert but I read something that might give a clue to one of your questions. I read one case where a man died on a fast b/c real hunger had returned but his doctor advised him to continue on the fast because he still had fat on his body.
My interpretation of this event is that true hunger returns when your body uses up its reserves of things to nourish you. If the amount of toxins is greater than the reserves, it seems to me that true hunger could return while there are still more toxins: the person must eat again to build up more healthy tissue and such before fasting again. If the amount of toxins and bad tissue is less than the amount of reserves, when true hunger returns, toxins will be gone.
Mind you, this is all from reading, not personal experience but something to think about.