As for the coin terminology. It was a system we thought others could relate to. It is a proven system in use for years. We changed in the second book MS to CS for chip state. Since we are dealing in chips not coins. The two can be graded or looked at in almost the same way. A baseball card can too. Each has an edge & each has a center. We do however have a lot of coin collector dealers among us. Many deal in both.
I hope I have covered all your questions now.

I do plan to address the ICG issue soon. Please be patient.