Metal wire question.
I just got off the phone with long time RC expert Ken Kehlet. (Does reviews for RC Modeler magazine among others.)
He said.......
"Yes and no. For instance if the metal throttle pushrod is touching the engine or making contact by rubbing against it. (Test this for yourself next time at the field by extending antenna and touching it to your engine while it's running. You will probably notice the servos glitching.) JR vs Futaba has been discussed on this matter as well. JR uses a single conversion system while Futaba uses the duel conv. The JR radios have had more reports of wire tapping than the Futaba's. " ( Basically it all depends on how your radio talks to your receiver.)

Another test is to have a friend you can depend on to really pay attention connect with you via cell phone or walkie talkies while your plane is running in the tail stand. One or the other starts walking away with the radio moving the surfaces as you would during normal flying. (Try to be easy with the throttle gimble but do go through all the levels of throttle throughout the test.)
Next pick up the plane and hold it at least 5 feet off the ground moving it in all directions just like you were flying.
Constant contact with your buddy should keep you from dealing with a full throttle situation I would hope....lol
Let the distance be as possibly far away as you can. Most RX are good up to 1 1/2 mile. So a few hundred yards shouldn't matter.
If it's going to glitch it will do it sometime during the test.