After watching the first 2 episodes a second time I noticed something:
It's China is it not? More specifically Hong Kong. Now I know it isn't exactly, and that it takes place in an alternate timeline but in the first two episodes it seems clear to me that Republic City is modeled to mirror that of Hong Kong as it opened up to the west.
The currency is Yuan, the architecture is a hybrid of Eastern and Western, and the music and set up reminds me a lot of many period pieces that I've seen taking place in that era and setting.
This is interesting because in TLAB each nation represented a different type of civilization. You had nomads (airbenders), militaristic (Fire Nation), rigid hierarchy (Earth Kingdom), village life (Southern Water Tribe), and loose hierarchy (Northern Water Tribe).
It seems like in this one you still have fringe people like the village Korra comes from, but Republic City at least seems to be a direct allegory to a specific place. We may even see an allegory play out that mirrors the xenophobic movement depending on how the anti-bending plays out.
Or maybe I'm reading too much into it.