Nice article Charles and great question.
IMHO, lack of proper training in the knowledge of "The Who, What, When, Where and Why of Tea" is where I have found teashops fall short or fail.
I have been in shops where I know far more about tea than the owner. That in my opinion is NOT
Acceptable!!! Especially since I don't know that much!
Your staff should know the ins and outs of all the aspects of the teas they will be selling before they even hit the sales floor. I want to be confident that the retailer knows what they are talking about, not just saying what they feel the customer wants them to say ... i.e. 'this is the rarest white tea'