RE: Reducing the surface area of the wings for going faster?
Parasitic drag exponentially increases as a function of airspeed while induced drag tapers off at high speeds. As airspeed is doubled your drag goes up by a factor of four! Where those curves cross is your best endurance airspeed. Now, parasitic drag can be further narrowed down into form drag and skin friction drag. Form drag is caused by air coming in contact with the frontal area of the aircraft. Skin friction drag is just what the name suggests. Howard Hughes had all rivets installed flush with the body of his H-1 Racer to minimize skin friction drag. He also utilized flowing fillets at the fuselage/wing junction to reduce intereference drag.
A high aspect ratio wing is a bit of a tradeoff since they offer a reduction in reduced drag but have a more parasitic drag. This is why airplanes designed to be efficient at lower speeds typically have high aspect ratio wings. Now parasitic drag can vary by factors as minute as air density but to a much smaller extent.
Essentially, a fast airplane boils down to having as little drag as possible with gobs of power. After all, total drag determines the necessary amount of thrust to maintain a given airspeed. Specifically regarding the original question: Don''t cut the wings like that. I can guarantee you won''t like the way it flies. As Yoda would say, "A modified wing only does not a fast airplane make." It's just not that simple.