Yes the 2.4 Ghz is for the throttle control, install the receiver, on/off switch, battery and a servo and you ready to go. You can customize a 2.4 Ghz car radio into a handle or hang the transmitter on your hip. Either way works. The servo controlled throttle is more precise and also allows for end point adjustment, and use the trim to set the idle speed.
I stopped flying 3-line almost 22 years ago. 3-line will work also if you like that better. At the nats this year we had almost every type of throttle control system possible, 2.4 Ghz, down the wire JR DSC controls, Clancy Arnold's down the wire, single channel and 3-line.
The model I fly is on the left (80" span), the model on the right is a Byron Original Ryan STA. I have since re-painted the camera plane and put on an E-Flite E60 electric motor with a 6S battery. I use the Tactic 650 2.4 Ghz radio for this model with BEC. The only thing the model carries is a receiver, speed control, 6S battery and the motor.
Fred