Basically the answer to all Qs here is "No".
Fast for health, you will build later if you don't indulge on bad habits, supps is a bad idea, fasting is abstinence and cutting-down not building up at the same time. Read the theory of it. Do sequentially. Cut-down - then stop - then rebuild.
You can't burn and replenish at the same time your engine. At any gas station it is mandatory to stop your engine, if you get what I mean.