1) The Planetary Union (PU) is an extension of US/EU governments. Take what we have now, move it 500 years into the future, and that's the basic intention. The League of Planets, however, is more scientifically oriented. All aspects of that culture are there to advance science. Freedom of religion is not a right. Religion, in fact, is viewed as a primitive belief and an indicator of lower intelligence. The League is run like a corporation, with all revenue-generating activities meant to drive funding back into research.
2) You will see "The Wasps" in THE CRYPT, either in Book Two: Shakedown or in Book Three.
3) The Triangle from INFECTED/CONTAGIOUS are modern-day, taking place in our time. They may or may not play into the far-future stories of THE CRYPT (500 years from now) and THE ROOKIE (700 years from now).
4) The subjugation of humanity is intentional, and a "fuck you" to every friggin' scifi story that has a human empire, hegemony, association, etc. All those stories are the same with different names for the government. The Creterakians are there to set up a different approach -- the benign overlords that will kill your ass if you get out of line. Yet despite this domineering society, there are still four major human governments (League of Planets, Planetary Union, Purist Nation and Tower Republic) that can't work together to overthrow them. However, even if those four did work together? They still can't hang with the Creterakians. Makes for an interesting universe where humans are not the end-all, be-all, and are also not being hunted to extinction (the other oh-so-common scifi plot).
5) Favre, at his best, wouldn't have made it in Tier Two. Maybe in Tier Three.