I have an Avionic RCB6i and was wondering if I could link it directly to a TowerPro SG90 Servo from the RX CH1 port to control the acceleration of a Class .15  Methanol Engine?

My specific questions:

1. It has a 3 pole motor. Will I be able to control acceleration smoothly or will it stick to 3 positions only (idle, half throttle and full throttle)?
2. Will it get damaged in the setup above if the throttle is help at a steady position for some time?
3. I am a noob with Rx's and Tx's so does my setup even make sense?

P.S.: I am using the setup in a custom RC Truck.

Thanks,
Areeb