RE: What is the most flexible pushrod system?
Richar L. Is right!
If you use the sullivan Golden cable (it's braded) or the Dubro Cable (braded) your problems will go away. If you already have the sheathing routed your half way there just get some of the appropriate diameter cable (braded) and run it.
Also if using quick links at the servo make you nervous, just put a Z bend in the cabe, then tin it with solder and install in the arm as you would a Z bent rod.
Darren