The main problem with this plane is not the size of control surfaces but the weight. Even with the standard throws the planes snaps really easy. You should try first to shave off some weight. Mine is flying nice and performs all basic aerobatic maneuvers but it's nothing more than a decent sport flyer. It was my first plane and I didn't touch it in a long time. I don't think you can modify it easy to perform well as a 3d platform. Sorry for being so nihilistic about it, it's just my opinion and I would better buy something else or build from scratch than working a lot hoping in some magical results.
Again , is just my opinion.

Boby