I'm interested in how powerful charismatic is (+1 happiness to alien pops) since we don't know yet how happiness works.
It may be, if not excessively powerful, then somewhat useful once you are a large power. Most bonuses only apply to the race itself, while this seems to be a nationwide bonus to everything but the primary species, so your xenophile and multi-species leadership empire is now more content overall.
Some traits, I suspect, are better for xenophobic empires. Decadent obviously,
but also talented and quick learners - because an xenophillic race will likely have multiracial leaders, as the game goes on, meaning that the bonuses would not come as much into play. Quick breeders and adaptability would also matter to better keep the other races down and the primary species numerous and widespread enough to retain a dominant position.