Hey Doug -
The intersection selection buttons appear on the Zwift Mobile link app on the Actions page (the one full of blue buttons). They only appear while you are in the selection area, the same time they appear on screen. You should see them replace the ‘Elbow Flick’ and ‘Wave’ buttons.
We do not offer a U-turn on Richmond, but in some places the route of the course has streets running parallel to other areas of the course. Everyone is riding in the same direction on the course, but can be riding in two different physical directions depending on the location. So everyone is riding in a counter-clockwise direction, but depending on their location in the lap, a rider may be going west, and see other riders travelling east on a parallel street.
Hope this helped! Ride on!