This plane as far as I understand was designed for Freestyle and its control surfaces are huge, well as the control surfaces are not already cut so if you like you can make the control surfaces smaller to add stability to the design.

As far as a .61Fx yes I think would give you the power for what you are asking for.

About the hinges I just decided to make them centered, also you would not need the clearance for +/- 45 Deg. for the kind of flight you describe +/-25 Deg. should be more than enough.