For this next iteration of my steps, I was not able to go back and change the sculpting of the shapes in Zbrush. But I was able to start the sculpting of the circular wall behind the steps. They are not quite as chipped and rough as I would like, but I got a good start on them, as well as getting the basic texture.
In regards to the texture of the steps I tried adding some light spot in the rocks from where areas chipped off to add more varying color to them. I also added a layer of moss/lichen that has grown on these old steps. This is just an experiment to see how it would work, I plan on adding a lot more than what is shown here. Once I produced the layer of the lichen, I used that same map and converted to black and white and used it as a bump map, to add some height and thickness to the lichen to help prevent it from looking as if it was just painted on.
The comments from Dave and Megan were that there still needed to be more large-scale varying color in the stone. The light spots aren't coming across enough and there should be some dark spots as well as light spots. For the lichen, it is working well and I essentially have the go-ahead to keep working with it. There should be some varying color in the lichen as well, right now it is just all one color. These techniques for the stone and lichen still need to be applied to the wall as well.