RE: Linkage layout/concealing linkages.
for your ailerons Id use torque rods and centrally locte your sero/s on the centre of your wing. for your elevatoe theres no reason I can see why you cant solder an arm to drop into fuse to attach a linkage to and keep it all inside. I have done that on elevators with a number of models including my first large (102'ws) laser. just make sure your soldering is up scratch