Hi Bill,
In general to edit any barline, just click it directly, then select the type of barline you want to change it to. So yeah, for the first barline you have to select it, then after you've changed it to a Beginning Repeat it will appear to the right of the clef symbol.
Thanks for the step-by-step of what you did - it is always helpful to us to know what users are trying to accomplish and how they are trying to do it so we will know how to tweak the software in the future to make it easier to use.
I'm looking forward to hearing the whole piece
ttfn,
Sherry
p.s. Have you given any thought to perhaps using different instruments for the different voices? Over the years we've had some pretty creative choir and vocal ensemble coordinators using different instruments to help the members differentiate the voices they were supposed to be following. Just a thought.