A number of aircraft I'm familiar with use the ailerons for more than one task. Some blended the functions mechanically others via software. It's not that complicated and many model flyers do the same thing particularly in high performance gliders. Google "snap flap" on DLGs for example where the wing trailing edge device is used for pitch trim as well as Roll, High lift and High drag(lift dump). All the functions are mixed in the transmitter in that case.
As for empty wings snapping off!
I flew Tankers and it never happened to me even when landing on fumes! We did have strict rules about how much centre tank fuel we could load and how we considered that fuel in the mass and balance calculations.