This post almost nailed it. The only thing I would add is that elite and elitist are not mutually exclusive. You could have all sorts of world firsts and the top gear on your server (elite), but if you are a jerk to other players and aren't interested in helping anyone else improve themselves you are probably an elitist.
Not sure I agree. Elitists by definition have a sense of entitlement. If you feel you are entitled to something that others are not then you are a jerk.
Note: there is some level of entitlement inherit to the game. For example you don't have a sense of entitlement because you think only people that complete 'Glory of the Cataclysmic Raider' should get the 'Reins of the Drake of the East Wind.' You are elitist if you think that other people that have completed 'Glory of the Cataclysmic Raider' don't deserve their reins because they got them later than you did.