So mutch space in the back for battrys. wheels and steering rack would be needed or even simpler single motor on a 5th e scooter wheel located at the front in the middle would work and give ultimate manoeuverability in tight spaces.
Yes on its own use a ADC throttle, on the ADC pins. The throttle connects to ADC, GND and 3.3V. A second ADC throttle can be used for braking or reverse.
I was think is it possible to have 2 one as a over ride via a remote for the adult
It’s a little jank, but you could set up a foot pedal under duty cycle control for accel/braking in one, and have the remote set up as brake only. I know this will work with ADC control, unsure about PWM