Actually mine weighs 15.4 - I mis typed it earlier!
The rudder servo is in the lower hole provided and I used a single pushrod on a 8411 JR servo.
The setups I use on all my planes is the same -
Max deflection possible for goof off flying - then pull it all back to half that and add expo to suit -
On the JR that is typically 70% on ailerons and 40% on elev and same on rudder .
NEVER reduce throws to "just enough".
learn to fly thru all maneuvers - including snaps -
there is no correct setting for these , as the combo for level flight is much different for verticals and 45 degree lines .
The reason being that gravity forces ar much different in these attitudes.
As for mix - for precision flying - first balance the model such that a cruise speed knife edge pass require little elevator correction to prevent tucking.
Then mix in what is required .
many flyers try to setup for the so called 3D stuff - then mix to get good precision flying-
It can be done but it is the hard way to do it.