You won't need Slic3r or Pronterface and Creator can do all the fixes that you're probably doing with Netfabb studio. So, yes it does have all the capabilities of those three combined and I think it does a better job. The Configuration_h file is a separate thing. It's used to configure the firmware running on the board controlling your printer and you should only have to set that up once when you first built your printer.
Thanks Karl; that's good news. I plan to buy Creator soon.
One more question: As I recall, Netfabb allows me to identify the layer where I want to make a change ... I may want change infill density at a certain Z level. A good example is the Buddha, where I want infill for the base, and print hollow from there to top.
If Creator can't do it all, Netfabb could identify the layer (Z location) where I want to change infill. Would I then be able to tweak the Gcode using Creator?
RichRap has some good ideas for applying this capability.
Is my memory correct in thinking you're in Cincinnati?
Creator doesn't currently allow changes at an arbitrary Z-layer. We've tried to make things as automatic and intelligent as possible to avoid that level of detailed editing. You can preview the G-Code by layer to identify the location where something might need changed, but you can't edit that layer alone.
We do have a few features planned for the near future that will help make this easier, but it's not included at the moment. If you have some good ideas about how to implement that capability, we'd love to hear them!