<<Every critical skill will need to be duplicated multiple times among the crew. Indeed everyone will need to know a little bit of almost everything.>>

Ditto. The mission will have its pecialists, but the crew should be cross-trained to substitute for each other in case of the loss or incapacitation of a member (or even two).

My ideal crew would be an even number--four or six--with an equal mix of men and women. Better yet, make them couples, for mutual support and reduction of sexual tension and power plays. I strongly suggest that the crew be trained on the ground to live in close quarters for as long as the actual mission would take, or at least as long as the transit time. This will not only show that they can handle it, but will give them an opportunity to learn each other's responses and sore spots at once, without any unpleasant surprises in deep space.

__________________
"He fell for her like his heart was a mob informant and she was the East River."

--Anonymous