no one is evil, its just that people associate the enclave with evil(blasted karma system) their plans are no different from anyone elses: get rid of radiation and save the world from the world. but who gets in the way?
I associate with with action and their intention (their mean of rid of radiation involve killings of many people even with a tiniest amount of radiation). I do not really care about the "Karma" system and I do not need that to tell me whats good and whats bad.
In my game, they're not evil. In your game, different story. Hurray.
Its a experiences of what any bad guy will think up. They think they are the good guys.
I could get into the war time soldier argument all over again. He's also shown as a person who doesn't want to see the wastelanders die, and would rather gain their trust. Seems pretty gray to me. Dark gray, if you want.
Also: your character is a murderer.
Ummm, if that the case, then there will be no need for an huge assault to the purifier and rather, just talk face to face.
And PC-wise, that really all depend on who and how they play it. I rather doubt he a murderer if a bunch of people try to kill him/her first.