The genius of The Witcher 3 is that it removes the player from the standard "heroic" role of the Chosen One. Ciri, and not Geralt, is the Chosen One in this story. At the same time, however, the choices of the player subtly affect the outcome. Does Geralt encourage Ciri or does he doubt her? Does he let his protective instincts overcome his judgement or does he trust her to do what's right for her? Does he rebuff the White Flame or does he go along with his wishes for his natural daughter (to whom Geralt is much more of a father)? In other words, parenting. The White Frost (I believe) is beaten every time, but the fate of Ciri is utlimately tied to these choices. Does she die, become Empress or a Witcher? The latter ending is considered the best one, since that's what Ciri really wants to to do. Storywise, I can think of no other game which does anything remotely like W3.

As for the politics, obviously the game is influenced by our real world issues, but if we want to be honest with ourselves can we imagine the state of the medieval world being much different if there were "non-humans" apart from different religions/cultures to contend with? Geralt is apolitical (tries to be) because it's his job as a mercenary to be so. Furthermore, leaving the world to monsters is not a choice. Geralt does not fight his battles on a political spectrum, but on that of Chaos vs. Order. Monster vs. Human. The main point in the game's politics is not so much to make a commentary about liberalism or whatnot, but to demonstrate that this battle is not always about Evil vs. Good. Not unlike The Walking Dead, the point is that humans are not always good and "monsters" are sometimes victims and products of all-too-human evil.

You do make some interesting points, but I wouldn't go so far as to pin any political worldview on Geralt. He simply goes along with human society, such as it is, because his true calling has little to do with politics. When he does interfere it's rarely a choice and when it is, it's a moral one, not political.