You should be fine with both the battery and the tail offset. I'm sure that Cox didn't design their plane's ESC to be operated at its maximum rating, so the 16amp battery should be OK. As far as the tail offset, foamies tend to fly somewhat sloppier than their wooden counterparts, so the slight amount of sloppiness due to the offset should get lost in the overall feel of the plane. I have a ParkZone J3Cub that I bought two years ago as a used plane. It has significantly more misalignment than what your plane has, but it flies perfectly well. Of course the J3 isn't capable of the same maneuvers that the Eagle can perform, but I think that your plane will fly just fine as it is.