KJGOFF, I am not certain why you wish to add a counterbalanced rudder. If you plan to statically balance the rudder, that's one easy way to do it. But build the rudder as light as you can If you want the model to have a different knife edge character, that's another reason. If you just like the look, that's another. Generally, adding a CB on the rudder will have an aerodynamic effect. It adds control area above the refence line which will induce more yaw when actuated as well as roll. I suggest you go easy on the amount you add.

On the other hand you may stay with stock rudder and fin and try adding fixed gear rather than retracts. That automatically adds side area where it is needed for a greater rudder effectiveness.

The wing is very large and will tend to perform things like snaps or spins almost sluggishly. That may be fine for your style of flying so it really depends on what YOU want the model to do.

If I was to re-design the model I would reduce the span down to around 74", reduce the tip chord to about 8" and keep the root chord the same. I would increase the thickness to around 12% to offset the reduced drag of the smaller wing, and to allow for other mechanical advantages. Stab area reduction would also have to be done, down to around 250 sq inches give or take. The stab span would be reduced to around 35-40% of the wing span. But that's me, and I would be re-designing with a different purpose in mind: F3A pattern.

regards
mattK