Sure they suposed to close mind people but Terramist bomb, they are learning to cooperate with humans and we are learing more about their culture. Sure they have some similarities with X-men but they could explore the cosmic area of Marvel Universe which seems to be very popular today. They dont usually have lot of enemies but there isnt a group with list of huge and importante currently solo villiains. And because they werent explored very well yet, that means that they have a huge untap potencial to be explored aside being created to be Kree´s weapons
He believes that he should be the protector of Earth and not Superman. But i wouldnt never Lex Luthor alone in Watchtower or touch anything if i was one of JL members. Because that will be biting on their asses one of these days and he is more dangerous than The Joker.