You really need to invest in a higher watt iron. You will need that later for the main wires anyway.
Hook each arm up to the controller to check the spin direction because the wires could be crossed before coming out of the motor. Mark the direction of each one. If you need to reverse one just swap any two of the three wires.
Paul didn’t include a second switch with batch 4 because it uses higher volts and lower amps. The switch is rated for 300 amps which is what you will get at full throttle. However, the true problem with the switch is when it gets damaged from arcing. Therefore, I highly recommend a pre-charge switch or button to protect the switch from damage. In addition, I prefer two switches so each only has to handle 150 amps.
Here is a link to the pre-charge switch I designed. Scroll up in the thread to get more details about how it works.