Heh I hate to say it but I seriously doubt we are the "ultimate" violent species in the universe I mean odds are there are others out there that are just as if not more warlike then humans Authors just tend to lean towards the inferior brutish human because it makes a good story point to beat a dead horse on how humans need to learn to work together in peace and harmony and lala because LOOK the rest of hte galaxy does
If you ask me we'd probobly end up like the Earth Alliance in Babylon Five either buy or Steal advanced alien tech unify what governments we want in a stronger version of the United Nations and then head out into the galaxy with the same attitude we head towards other countries 'Be nice and so will we mess with us and we kill you".
The Star Trek Federaton is FAR beyond what we humans would probobly ever do because let's face it even if we met friendly aliens and said "Okay your nice" we probobly would not want ot share our ships with them.