Ed,
In the "hydrate" stage I will be soaking in wet sphagnum peat moss, in the refrigerator. Last season I found that hydrating will decrease the rooting time by at least a week for older stored cuttings. The cuttings will spend weeks "hydrating" in the normal pre-rooting steps anyway, this just speeds up that process. The Sphagnum moss decreases the chances of mold growth. Yes I will be using rooting hormone on the bottom cut end only.
Misting just the surface, if it dries out in the rooting phase, the exposed cutting will be covered in wax. Misting in the growing phase refers to the leaves, to keep them from drying out.
Yes water is only added to the reservoir after the cutting has rooted and the mix is almost dry.
Pino,
No, there are no problems removing the plant from the SIPs. The wick is cut off below the cap and the exposed end is pushed through the hole in the cap. The cap is then removed. The root plug removal proceeds just like a regular planter.