Also as the Kit im getting is gonna be throttle only, will this mean the ebrakes wont be needed as the engine stops as soon as I take my thumb off the throttle?
You probably want some form of cutout, as when throttles fail they often go fully open.
Most times the bikes brakes can overpower the motor, so it's more about protection of the motor. However, if you have more power and crap brakes, it could be a problem.
Ironically, if you use the brake lever supplied with most kits you will have crap brakes.
There are other options though. Hidden wire brake sensors for cable brakes, DIY if you have hydraulics. You could also think about not having a switch but have an easy way to kill the motor in an emergency.
Sent from my HTC 10 using Tapatalk