I have this same plane and although I changed a few things with the servo mounting I don't think the antennae issue your concerned about would be the problem with the exception of a couple of items.

If your antennae is flying out the back end and can possibly make contact with a control rod or make contact with metal clevises or control horns.

I have seen one flier in our club install his pull/pull cables in an x fashion. Never could convince him that's not the way it's done. Although I'm not any kind of electronic/radio expert the thought of two wires rubbing back and forth against each other isn't good for anything and the cable on that fliers' airplane were bare metal. Oh, he did crash it. Went out of control right after takeoff and on previous flights he always had radio glitches.

And lastly, as bob_nj stated loose connections will getcha. I have a Giant Aeromaster and before I flew it for the first time my radio was acting whacky. Everything was new when I installed the radio system and after going through it I found 3 servo leads had loose wires. When I replaced the bad leads my problems went away.

Hope you get it whipped.