Just as a side-note to all of this - and understanding that these are the words of a born cynic (me) - the dynamic you are painting is starting to feel like Avatar, and not the element bending kind. Clearly your story is wildly different to James Cameron's Avatar, but there feels (and correct me if I'm wrong) like a running message that humans, when left to their own devices and scruples (or lack thereof), will be as ugly, cruel, avaricious and callous as the environment will physically allow. If that's a message you want to work, you're working it. If it's not.... you're working it, from what I see so far.
Actually what's happening in the setting is that humanity is being prevented from bettering themselves by evil kings that just won't pass on. The MC is from a fourth race that wasn't mentioned (though they're nothing special, they're usually naturally violent) and his quest is initially to find a new home but then is forced to go find a powerful artifact, humans will play a minor role (if at all) in the next story whereas here they're shown to control most of the continent and in general are not safe places for the MC to live (forcing him to find a home between his own kind, whom he is not aware are violent (his own tribe was an exception)). Humanity itself plays no major role in the story other than to make it clear to the MC that if he wishes to live safely, he'll have to go somewhere else. There are two other groups of humans in this setting, one of them lives in the mountains and are autonomous, SPECIFICALLY because they're aware of how the rest of humanity is progressing. The other group are black people who integrated into white human society specifically to avoid having their people decimated alongside the Nevoha and Arraqui (whom they live with peacefully and help). Neither of the other two groups are powerful forces in the world and do their best not to become enemies of the kings. The MC can't live with the ones in the mountains because they have a policy to take in no outsiders so as to preserve their ways, and by the time he meets the Elmir (black humans) he's reached a point where NOT searching for the artifact is not an option. One of the ideas is that humanity is slowing bettering themselves, but the immortal kings are hindering this progress majorly.
