You can use microbes and enzyme products together without issue. Microbes also make enzymes.

As long as the stem is green and not woody, then roots can easily form. You can speed up the process by scraping off some of the outer cell layer and add a little rooting hormone on wound for roots to form from.

I try to advise against using carbon based sources for raising or lowering pH. In small amounts baking soda and acetic acid are fine. But I would never recommend using carbon based additives for pH on a large scale in reservoirs. Carbon creates solids and sludge.

Every water source on earth has a little chloride. Don’t go thinking you need to remove it or that it kills microbes. Chloride is an essential element required by plants. Your plants would die without it.