I think you're all misreading what he wrote, and I think he connected some things that shouldn't be connected.
1. A starter motor theft deterrent relay simply disables the starter unless you know how to activate it, thereby preventing someone from stealing the car. You can put this on any vehicle you want to, even a schoolbus or a motorcycle or the Oscar Meier Weinermobile.
2. If your car starts in gear, then your PRNDL switch assembly on the steering column is misadjusted.
3. The fact that it's a 9C1 has no bearing on any of this whatsoever.
4. If your car always feels like it's in gear (even in neutral) and won't roll backwards when in R, then the forward clutches in the transmission are fused together and the trans needs to be repaired.