Rcpilet,

I also used carbon fiber pushrods (about 14" long) and have noticed no tendency to flex with the straight backmounting (servo to elevator half). On my MVVS engined plane I actually had to add about 2oz to the tail and move the servo/rx battery as far back as I could put it to balance. On the Saito engined plane I had to add 1.5oz to the nose to get balance. this plane has the battery all the way forward. But it is lucky for me I guess that both of my planes came out around 12.4 pounds and required very little weight to adjust the balance.
On my second plane I made the following change to mounting the wing that made things a lot easier and stornger. On my first stock built plane the front wing mounting holes the dowels go into strectch out after several flights and had to be reinforced. Additionally the plans method to isntall is a complete pain. Here is what I did. Install a 1/8" piece of aircraft grade ply (make sure grain horizontal) behind the backing plate the wing dowels go into. Put a dab of chalk or something to mark correct location on the end of the wing dowels and slide wing forward until they mark the proper location on the oiece of ply you installed. Now remove wing, drill the holes and you are all set.