Thank you all for the warm welcomes and the great info!
I'm starting to like the idea of grinding down what its there to level and then filling in the cracks and then putting on some sort of earthen floor to seal it. The limecrete is really neat! The wood is also a wonderful design. I'm looking for speed and cost effectiveness as I'm hoping to have this done before winter to enjoy some blacksmithing to keep me warm...err hot really.
I'm going to look into renting a grinding machine and see the cost of some sort of grout to fill in the cracks with.
I did some probing into a badly damaged part of the concrete and took some pics.