you can switch to Sbus in the transmitter, but it looks like it is all or none and you can't mix ibus/sbus and the standard PWM ports. I don't have any FlySky gear so I can't test to be sure. Looks like the Aura 8 might be the best solution.
if you want differential thrust, your throttle would need to go through the stabilizer (as the differential needs to be effected by the stabilization), otherwise like the aura, you can bypass the FC as you don't have to stabilize thrust in a plane (however FC that do have throttle going through them can use that to make some adjustments to the stabilization curves so that you get better stabalisation over different speeds - add the effectiveness of your control surfaces is effected by the speed of airflow over them.)