If you don't mind the pushrod hanging out the wing, then what Mark said, or a ball link at the elevator horn. For that matter, your flap-like idler thingie isn't a bad idea -- I'd consider putting it on the fuselage so that the pushrod isn't flapping around when you take it apart.
If you don't mind peering into little holes with a flashlight and cursing, put a threaded end on the pushrod and a ball link on the bellcrank, Then screw the pushrod in on assembly, and unscrew it on disassembly. This is how I put my profiles together, so that I can paint without having to work around a pushrod. Getting it reassembled repeatably will be a pain, though, unless you solder a jam nut onto the pushrod end or something.
Alternately, break the pushrod at around the TE of the wing, and put 4-40 couplers on the open ends. Then get a small-diameter steel 4-40 coupler from an electronics supply place (like DigiKey -- the amateur places will all have big aluminum ones) -- if the ends are screwed in tight, then you should have a strong, rigid, repeatable assembly.