I agree with XTOL 100%. Don't complicate a simple, wonderful model airplane.

This one is built bone stock, and flies as good as you could ask for. The modifications you are contemplating will add weight/complexity and give you very little, if anything, in return.

Save all that stuff for a larger plane. The Kougar is a simple little sport plane designed to teach aileron flying back in the days when ailerons were viewed with suspicion by the rudder-only "old heads"... It doesn't need any sprucing up or modifying.

And the balsa pushrods are quite sufficient. Dude, this is a 4.5/5 pound airplane. Built as intended, it has all the performance you could want. Yeah, you can put a larger engine on it, do retracts, dual aileron servo, etc.... but, IMO, you will destroy most of its great characteristics in the process.

I built this one for my grandson, and he flew the wings off it before he lost interest. Now that he has moved away, I bring it along with my big gas aerobat for a change of pace, since it slips in neatly in the cramped bed of my S-10 alongside that 27% Extra.

As designed, the Kougar is a pure, simple fun plane. Doing all the "modern upgrades", etc., while possibly interesting from a technical standpoint, defeats the purpose for which it was intended.