Nah ya really do not need a throttle as long as you can still apply human power and help the motor that is helping you.
The BBSxx ramps down when you stop peddaling...i never really like that but it does it anyway.
The Gear sensor does what the brake cut off sensor does....shuts the motor down...I use my brake cut off sensors instead of the gear shift sensor.
I lightly apply my brake lever/levers..just enough to activate the motors shut down, then i switch my gears...I found that the gear shift sensor
sometimes fails but i Always have at least one brake cut off switch/sensor...make sense?
All in all, ya do not need a throttle (they are fun and come in handy from time to time though), those brake shut off sensors can save your life,
some people like a gear shift sensor...I just found them to be another failure point as have many others.
The choice is yours really, do you want to spend more money only to find out later that it was pointless..