IMHO:
There are only 2 absolute must haves in nitro RC, a failsafe and an adequately strong throttle return spring.
The failsafe is easy enough, but hooking up a good throttle return spring can take some trial and error. You have to find the right spring and the right mounting location so that it will pull the carb closed if you loose power. You may have to play around a bit but once you do, you have worry free running. Signal loss: no problem the failsafe kicks in and all is well. Power loss: no problem, the throttle return spring closes the carb and the car idles happily away until you get to it and figure out what happened.