I purchased the same kit. Have had an issue with a clicking noise but Paul has been responsive and has sent out the parts necessary to fix the problem as soon as he had a reasonable idea as to what the problem was.
The kit itself isn't too bad, controller and battery are excellent, motor is...
I'm still waiting for my kit, I noticed the same thing regarding the 3 speed switch. I sent an email asking about this and was told 'the 3 speed is configured to us the CA3 analogue input' so I'm assuming you connect it to the aux pot connector.