I have been using similar pushrods (music wire, CF tubes, aluminum rings, 30 minute epoxy) for several years with no slippage. The CF tubes are actually carbon fibers in an epoxy matrix. Some roughing of the interior surface will ensure a tight bond between the epoxies of the tube and the new epoxy. Using a notch in the wire or threaded wire will prevent the epoxy from slipping on the metal.

I've tried pulling the ends out on post crash tests, and it didn't come out easily. Far more force than would be experienced by a normal control surface under the most extreme conditions.

Brad