RE: Effect of tappering a wing with a small chord
Taper barely has an effect on induced drag at large scales (5%). It's used more for structural reasons, lower roll moment of inertia, bending loads, etc. The scale won't matter, since it's an energy conservation thing...
You can get much higher maximum lift coefficients out of a tapered wing though, if it is designed with the stall occurring evenly across the span.