One question - some of the races get specific moves or stat bonuses as their racial benefit, while others only get the ability to have a specific stat bonus as an advance. How does this balance out?
Basically, it doesn't. Some races get a +1 or an extra move, some get both and a -1, and some get nothing, or they get nothing if they pick certain playbooks. Some bonuses partly reflect what Blair has developed for the races in his own campaigns, some I just made up because they sounded neat. Some races will have additional social advantages if you use Blair's Iridium Plateau setting material.
If all the races just had a +1, then they would balance out with normal AW characters. That's why I say to take a -1 if you're going to use an AW playbook.
Choosing to be Terran or Synthetic is a blatantly sub-optimal choice. If you're synthetic, you get to make up a race, basically, instead of getting an extra move or stat bonus. If you want to play someone from Earth, the rules encourage you to choose the Earth Man playbook instead of being a Terran Bravo, Thief, or Warlord. That's intentional. I'll probably write a Spaceman playbook in the future to better account for astronauts (and space aliens), and some specific synthetic races that have bonuses or are playbooks.