Nah. But he did challenge our interpretations of the righteousness of the Old Jedi Order. Luke was not raised by the Monks in a Temple with thousands of other cultural influences. He was trained by Yoda in a swamp, as an adult, with very little time to mature. He was always going to be "different". In Jabba's palace he Force Chokes the guards and pulls a pistol on the Hutt. Then he goes about killing everybody on a sail barge. Kaboom! Brave new world.
Luke teaches us that the heroism of the Jedi can only conform to the moral values of his writer and the cinema society for which it is to be presented. This is reinforced by the writers who wrote the EU books. Each writer admits to shifting the moral compass of the Jedi religion, (and it's heroes,) according to their literary tastes and cultural values. These variables are everywhere in Star Wars canon. Lucas himself enjoyed the thought of changing a few things when he crafted his prequels. Lucas made Obi-won Kenobi the "ideal" interpretation of a Jedi Knight. Not his earlier presentation of Luke Skywalker.
The important thing to remember is that Star Wars is a shared universe. Christians, Jews, and Muslims are all going to imprint differently upon the moral compass of it's religiously affiliated heroes and villains. Good and evil will always be subject to the fans interpretation. Just like it was to it's Directors, Producers, Writers, Concept Artists, Costume Designers, and Painters.
Did Luke Skywalker fall to the Dark Side? No. But is he human? Yes.
