What about overall happiness? If slaughtering an innocent would bring happiness to everyone in the world that no other action could, would it be the right thing to do?
For this question, i will use an example. Lets say that this innocent is believed by all the citizens of a village to be a witch, including you. (This village is for arguments sake the entire world.) In your opinion, it is right and everyone else but the person believed to be a witch believes it is the right thing to do. If you kill her, it would have been the right thing to do, according to everyone in the world and you.
Why does everyone, including me think this "innocent" to be a witch? How much happiness will this really bring the world? I mean was it the death of Hitler that brought that world happiness, or was it the satisfaction that his very real threat was at an end? If this innocent never was a threat to the world, where is the happiness?
If we're going to use an example to prove that morality isn't easily defined then using a Two Dimensional example is a bad idea.
Back on Topic:
The last 3 episodes aren't suppose to be deep. They literally ran out of money and had to work with what they had. Then Eva got big, now you have the (far better) movie remakes coming out.
I always thought Eva was a fun watch though. I was always amused that Shinji was the embodiment of the Female Protagonist in anime at the time, while Asuka acted like the fireyheaded male lead, and Rei acted like the Stoic male lead.