Re: Differences between female & male practitioners
I know of one karate dojo that have separate karate classes for women, partly geared at immigrant groups where the girls would not be allowed to train with men. They are successful - they do have a market, and I think they train pretty good karateka (not that I can really judge).
They do have a female yudansha teaching some (not all) of these classes - and she's GOOD. I'd think that's a necessary ingredient (one of many) to make that concept work.