good points Jim.
workshops are an excellent idea.
I notice Lewes Folk Club,are one of the few clubs that do this.
recording oneself,is a way that singers can learn to improve.
in my opinion workshops are useful for singers/ musicians to improve their technique,a good starting point.
it is debatable whether singing with interpretation/ feeling can be taught,[imo]it can to some extent.
of course all singers performances will vary every time.
Pat Mckenzie made a very valid point[some months ago]about a singers interpretation of Lord Randall,how the traveller singer was putting all her feelings about being settled into the song she was singing.
singing is about expressing[whats happened to you] and I am not sure that can be taught.