Either will work, but i have always gone for a belt and braces approach by using epoxy. I usually use a high strength and long setting epoxy which allows me to work with it and make sure everything is perfect before leaving to set. The long set epoxy also makes for a stronger bond.
On the boom support braces i mark how far the carbon rod goes into the plastic brace ends and then rough up the end with sand paper. I then align the ends making sure they are parallel with each other and drill though the carbon rod with a 2.5mm drill bit, once thats done i epoxy the ends of the carbon and fit the plastic ends and line up with the holes, i use an M3x10 Button head bolt to secure in place. I do this for all the ends and then clean up the excess epoxy. I can leave these to set overnight or fit them straight away.
With the tail push rod i use the same long set epoxy and after i have cleaned the carbon rod and threaded rod with alcohol or solvent cleaner to remove any grease i force some epoxy into the tube and also onto the threaded rod, i then feed the rod into the carbon tube.
I have never had a problem using this method but i have also started fitting the brass blade spacers (5mm-4mm) from sets of blades or heatshrink over the ends of the carbon tube where the pushrod is located as an extra security method.
Hope this helps
Cheers!
Ross