Not very - it doesn't need to be. Sharpened and re-profiled it with a 80 grit flap disc on angle grinder and took it to polishing wheel + leather strop. The shine is just for the looks.
Good. You probably don't want a hatchet to be that sharp. You're not going to be doing anything delicate with it. Sharp blades have the edge bend or break easily.
Yeah, edge that sharp serves no purpose on axe. It'll bend and then be dull again. Shallower point with the burr removed is more durable and stays sharp(ish) for much longer.
I have no idea. It was one of those black fibre ones that you attach to a drill. I had originally used it to polish stainless steel after welding. Stropping is the difference between reflecting light and reflecting image
Not even close. That level of sharpness would only matter on axe if you intend to use it as a weapon. Chopping wood with edge like that would just bend it and make it dull prematurely.