The other option that works really well is throttle axis range, change forward only to full range. Then full back on the throttle is full reverse, full forward on the throttle is full steam ahead, and mid point on the throttle is stop. I'd also suggest you dial in some deadzone on that axis, so you aren't having to be millimetre accurate. On the pic above, there is a + sign next to throttle axis, click the plus pops out the options for the deadzone, whcih is just a slider. I'd say put the slider to ~the E in dead zone to start with.