Reddit mentions of Mechanics of Flight

You can definitely play with the S&C side of things (tail sizing, aileron sizing, flying wing, etc), but you'll have to write the codes yourself. A good place to start is Mechanics of Flight. I'm not a CFD guy, but I can tell you that it will be hard to quantify.

How big is the plane? It's a lot easier and cheaper) to use electric motors compared to nitromethane for most of the common r/c scale.

OTOH from my flight mechanics course 4 years ago;

What you need to consider is not torque but power. Very simply put, power required to make the plane go forward is P = VD with the speed V and D the drag force. You can estimate the drag from CL/CD plots.

EDIT: If can you can get your hands on a pdf or cheap copy of this book I'd recommend it, at least for the few 3 or 4 chapters. After that it gets pretty deep in advanced dynamics for someone with little background.

http://www.amazon.ca/Mechanics-Flight-Warren-F-Phillips/dp/0470539755

The engine needs to output higher* than this due to propeller efficiency.

I understand. Have you thought about visiting universities near you, which might have aerospace engineering related program? You might be interested in student competition programs (perhaps the team leaders will let you hang around & participate), such as DBF (Design Build & Fly) and AUVSI (Association for Unmanned Vehicles Systems International). As for additional textbook resources, I happened to use Flight Stability and Automatic Control by Nelson for upper division flight control course, but it is riddled with errors (make sure to read the errata). I also recommend Mechanics of Flight by Philips for the same topic.