Although I'm just a beginner there are two comments I'd like to make:
First...some electric systems (specifically the Hobbico Superstar and Futaba 4YF I started with) have a characteristic that can create a different risk...not enough power to control the aircraft on takeoff to keep it from becoming a hazard to bystanders. If the power to the receiver is turned on with the throttle on the transmitter at any position other than full off, you will only have throttle from that point up (in other words, the starting point will be the new off position. If this is, for example, with the control halfway up, you will only have half throttle to try and fly). Although you still need to arm the ESC by moving the throttle to full and then to off you only will get the amount of throttle from where it was when you turned the receiver on.

Second my instructor warned me of a risk from priming a fuel engine with the glow starter attached. It is entirely possible for the engine to start, and since the approach to priming was to cover the open throttle with a thumb while manually turning the prop to get fuel to the engine, it would be easy for an arm to be in the way if this unexpectedly occurred.

I guess the real message is that model aircraft are not toys, but more like power tools, and should be treated, if anything, with more respect in recognition of the damage they can do to property and life.