See the manual section entitled THE ROBOT, page 11.
Because you must wire the sensor to one of the digital inputs, not necessarily to pins 6 and 2, but to ground and your choice of digital input (see the Control System Manual 30), the current rating of the switch is irrelevant. You absolutely may not turn on a motor directly with one of these switches.
Of course, you must be either use an input that works with the default program, or be able to program the controller to use the input you choose.
If you have any questions, leave me a message on the team188 board.
http://www.team188.com