They never did answer the Hugo/Hurley name. Maybe Hugo decided after his time in the mental hospital to seperate himself from his past by calling himself Hurley.
The Others thought they were the "good guys" because they felt they were chosen by Jacob and both the Dharma Initiative and our "LOSTies" were intruders.
They thought they were the good guys because they saw themselves as protecting the Source from those who would use or abuse it. Everything else they did was justified because of it.
Actually, I have two questions:
1) How did Hugo acquire the nickname “Hurley”?
2) How could the others possibly think of themselves as “the good guys”? (Actually I'm not real clear on their motives for a lot of their actions.)
By the way, if anyone hasn't heard the news, the complete series box set is supposed to contain a ton of extras that will give us some more concrete explanations of some of the shows mysteries. Supposedly it’s going to contain a whole series of new DHARMA videos which will give us more details about that organization's history and inner workings. And according to rumors on several forums, there will also be some additional flashback scenes featuring Jacob and the Man in Black which will give more details on the island's history and purpose.
The only addition to the story is a "bonus episode" called "The New Man in Charge" which chronicles Hurley's first few days as caretaker of the island, and also features Ben and another character whose inclusion I won't spoil here. The episode does provide a few answers, but all in all, was a bit of a letdown. I believe it's also included on the season 6 set, so you should be able to watch it.