Nice to meet you, Tony and thanks for the kind advice. Re my question #2, your two pieces of advice--get the color file right first and to check the slider extremes-- are quite helpful and fit together well--I see , after some experiment, that the extremes of the color sliders can be very different with a differently-colored starting point. Thanks.
Re my first question, I failed to give enough information. I see I need practice even at something as 'straightforward' as forum questions. My idea of trying a B&W conversion was a response to seeing the wife out-of-focus. I wanted a portrait of both of them and the out-of-focus wife is, to me, an irremediable flaw in the color shot. Now, I usually read B&W shots as more ambiguous, or more evocative, or both; when compared with a color shot of the same scene. So, my B&W conversion was a try at salvaging the shot by making the wife an interesting second subject even though she was out of focus. Does this make any sense?