Ditto on EZ connector... EZ on... EZier Off.. especially where vibration is concerned.

I dont use servo trays for the throttle pushrod for precisely the issue you mention. Mount the servo to the side of the fuse that has the throttle arm and 95% of your routing will be solved. With flexible cable you'll need to support every bit of the way. Without full support you'll have issues getting minute adjustments to work properly for example between very low throttle and engine cutoff where a small arm movement wont be transmistted to the throttle amr due to bending.