Is the receiver wrapped in foam?
This could have also been your idleing problem? If the receiver is sending erratic commands, your throttle servo could have been glitching also--giving your idle problems. Then again, you said it only showed up at high throttle, so never mind that.
I definitely wouldn't write it off as just a bench problem. Get it fixed before you fly it, or it will cost you the airplane. You could have a damaged crystal that only shows up during times of high vibration!
Is your crystal taped in?
I agree that your receiver antenna should be fully extended and routed properly. However, with no other radios present, your radio should not be glitching with your TX antenna collapsed. This is the basis for all of our radio checks. Do not raise your TX antenna and assume that the problem is fixed. You should not have glitching either way. The only glitching I've ever seen with my antenna down was at the field when another pilot had his TX on. standing right next to me, with his antenna fully extended. I was getting glitching.
I assume that your batteries are charged? (both TX and RX)