It is really good to have your emergency stop switch in, forgot to say that in the mains in, the emergancy stop has 3 connections switches. 2Nc and 1 no. The nc ones are red, no is green. One of the red switches are wired into the spindle mains supply to break mains power to the spindle controller. The other nc I have wired to the motor power so that the 28v to motors are killed so machine stops moving, but electronics are still powerd not the stepper drives. The no I have wired into my BOb so when it's pressed mach3 sees this as an emergancy stop.

the end stop electronic switches the small orange switches bolted onto x y and z, are important as the axis can ram into the metal frame of the axis, and potentially on the x it could let the ballnut off from the screw, although it would hit the chassis edge before, so... Yeah. They have 3 wires, black brown and blue, they are powered 10-36v so I power mine from 28v or was it 18.. The signal wire is connected to the switch input in your controller, and ground is put onto common ground.