Tee, your description above is pretty much my formula, too. You're doing it right.
I would avoid the cedar shavings, though. Cedar has some oils that can be bad for some plants and some microbes. Also, it'll never really break down.
Height: as high as it takes. I've heard of hugelkultur beds of 6 feet tall. Mine usually end up about 2 feet tall.
I dump all old potting soil and dead plants into the compost bin where it eventually finds its way to a hugelbed. I don't add them directly but I see no reason why you couldn't (assuming no diseases are present in the potted soil)
Fresh green materials: yes! I add as much of that as I can find. When I built my big mandala shaped hugelbed, I cut quite a bit of grass and immediately raked it up and put it on the bed. The fresh green material is full of nitrogen.
Plant right away, but be prepared for the plants to struggle during the first season. During the first couple seasons, plant things in the bed that are not heavy nitrogen feeders.
