engine idea when put into gear

[Numplumb]

The neutral switch and the clutch switch and cruise control are spliced together in the loom and go to the ecu.
I think the clutch switch is a push to break switch, not sure about neutral switch but probably is the same, the other side of both switches go to ground so they are holding something low until you change there state by pushing the clutch or putting it in gear.
I would think the clutch switch could be done away with but not the neutral switch.

Google the Miata King Mike he has a you tube video about the neutral switch jamming the gearbox in reverse.