I haven't had the chance to read all the way through this thread yet , but wanted to give my input as well. I have a little 50cc yak i just built and maidened last week , and i could not set up a choke servo on that airplane/motor combo. It just would not work given where the choke is located and how the airplane itself is built.

I do have my throttle set up so if the trim is all the way down , it will kill the motor. I also have 'fail-safe" set up so she goes to idle if i we're to have some kind of a radio issue. I also chose to use a smart-fly optical kill. I had never set one of these up and it was extremely easy , and i honestly feel safer when i'm flying now. Just that little extra safety factor helps the confidence a lot.