MMM and mechanical brakes question

Thanks all, i was just worried about the electronics in the esc as the servo i suppose is more basic in commparison and i was not sure if they could run together. I do have spectrum radio gear and i think it can do mixing but i may need more info on setting it up that way' Why is it the better way and the differance between the two setups.

Oh i also need to shorten the shaft on the motor as it enters the battery tray and hits on one of the lipo's thought it might be ok seeing these things come out with the castle set up as rtr but its way too long. Should i just cut it off with a small grinder and cut off wheel.