I first discovered the Red Clay Ramblers when they were the musical
accompaniment for the Broadway show (then touring) FOOL MOON. I thought they
were absolutely terrific, and still do. (And the show's terrific too; if it
comes to your town SEE IT.)

"Where did B5 start? What was the germ of the whole idea? Who were the first
characters? Were any characters conceived as men that ended up as women and
vice versa?"

No, the men were men and the women were women (and they LIKED it that way).
The primary "germ" of the notion was the setting in this case, a locale where
the stories would come to us rathre than chasing new worlds every week.
Obviously you need a command staff, and I began filling it out from there.
Then, one day, the whole story just sorta unfolded in my head in a moment of
total clarity. That happens sometimes....

jms