How should we wire the photoswitchs?

[Al Skierkiewicz]

Al,
Correct on all counts. To add one thing, the power lines need insulation in some form. A terminal block handles this nicely, insulated splices also work.
The chances of going below 10.4 volts is a guaranteed condition when ever you start to move. If like most teams, you are using 2-4 CIM motors, the current at start is enough to drop a couple of volts across the battery internal resistance. Add wiring losses and you will find that the power to the sensors if going to be near drop out a lot of the time.