Questions on Autotune and Mid-Throttle stick

Hello to the complete Team with a parachute related question.
ProfiCNC Cube with redundancy BEC on rail and RX powered from SbusIN with redundancy BEC on RX(board for this is still being made and tested).
I want to connect the parachute directly to the RX and triggered manually from there radio but in addition i would like to have the same channel be able to kill the motors on the Hexacopter.
The whole purpose of this is in case the FC fails completely not to have the passthrough for the parachute but simply be a manual command from the operator.
I know it might sound complex, but at the same time i think it will be secure and any mistakes will be operator mistakes. My proplem lies to the following facts.
a) Can i split the RX PWM signal to two points without any issues? on the parachute side it will mean trigger on the FC side it will mean kill the motors. In case failure is broken UAV and not FC
b) Skycat trigger states : *If launch is activated when battery is connected, parachute will not be ejected. Trigger will not accept eject command until channel is toggled OFF and ON, i.e Rescue Radio is switched OFF and ON.
And for this i was thinking a 2 position switch that i will add a push button. Toggle on -> push ON -> release button then goes Off again. (also for security that someone does not toggle by accident)
My problem is that this will mean that motors will disarm and arm again so the question is(unless crash has been detected).
If i put channel 7 to Parachute release, but actually have the trigger direct PWM from receiver(ch7), would this stop the motors while activating the parachute?