I know 'internet=drama', but I'll never understand why people will actively dislike one another over a game.
That said, I think the cultural differences between the Empires with regard to views on 'idle socialization' will at least cause some modicum of friction, albeit manageable friction. When you take into account characters which have an unpleasant history, or organizations with violently opposed agendas, those things won't be set aside for the sake of an admittedly gracious host.
Then of course there are those personalities who thrive on using these events to spawn shitstorms, a la New Eden's Andy Dick.