Not a nitro guy, but if I understand the Opti-Drive correctly, it is designed to prevent the tranny from switching from forward to reverse and back while the truck is in motion, prevents damage to the drive train. Because you are going to use this in an electric truck you don't need the Opti-Drive at all. (Not sure as to how you are going to mount up the motor to the tranny...)
I can't say that this is the best fit for that truck, that tranny is designed for a Traxxas 3.3TRX engine, which turns at very high RPM (20-50KRPM); using this with an electric motor will give you all kinds of torque, but little speed.
As far as the ESC and RX goes, plug the ESC into port 2 of the RX, the servo into port 1. With the tires off the ground, turn everything on, make sure you have throttle control and steering. Adjust your channel reverse if needed to get both channels going in the directions you want them to. Next, turn everything off, zero all of your pots on your radio, turn it on, turn on your ESC putting it in calibrate mode (follow the directions for that ESC).
Turn everything off. Pull your servo horn off of your steering servo, turn on your TX and your truck. With the front wheel as close to straight as you can get, put your servo horn on your servo, it might take your front tires a little off center, this is ok. With the servo horn on, turn off your truck, put the servo screw in and tighten down your servo. Turn the truck back on and adjust the pot so the tires are straight. Just remember, that radio does NOT have end point adjustments (EPA), so it will be possible to bind your servo up by turning it too far.
Hope this helps.