It's good to see you are reading more extensively than the recommended list Grahame. We are actually referring to this article in the next course so you are ahead of the game. I had to check what I had written on P470 because I couldn't remember.
The suggestion is that coaches who have previously been performers may be better able to interact with athletes in that sport however it does not suggest that these ex-athletes will all become coaches or that they should be fast tracked. I actually have not seen any evidence that the concept of fast tracking works - it really depends upon a number of factors. I tend to consider that ex-players may or may not make good coaches - to me it would be similar to suggesting that someone who has been a patient in hospital would make an excellent surgeon!
I'm not sure what definition of expert you are referring to on P472 but I do like the characteristics of expertise on P465 and I have used them in a subsequent (2012) paper looking at definitions of coaching expertise. I do think we tend to use the word expert too easily - I think there is a big difference between very good, highly skilled and other descriptive phrases but not all of these are experts in my opinion. Still a lot of work to be done in this area.....anyone want to help?