Hoo boy. I typed this up back during some site issues and couldn't post. Here's my giga autistic look at Korra. Part 1 of ?
[Link to a post that's long gone now, saying that bending ability and class are different things, and the source of what I'm quoting]
This. IIRC the first episode of Korra shows Mako lightning bending to generate power (magic equivalent of pic related). If bending had a realistic relationship to class, it would be to divide the working class according to how useful they are for labor. Since the bourgeoisie do not have to do labor, bending would confer little benefit to the ruling class (just for self-defense as Tarrlok shows). The big losers would be working class non-benders. Their labor would be useful, just not as useful as the labor of benders. By all appearances in the Avatar world, though, benders are a minority of the population, probably under 10%. Benders would probably fit in like an educated working class, whose labor is significantly more valuable to the rulers.
This isn't entirely true. Looking at The Last Airbender, there's definitely a tendency for benders to be in the noble or military classes. Since bending is partially heritable, benders who get into power are going to beget more benders in power, and their abilities will likely only help them. In The Last Airbender, the four nations are neatly divided according to bending ability, which would be a natural consequence of regional ethnicities sticking together through feudalism. Though not really shown, benders being in power would most likely get woven into a nation's ideology regarding right to rule and so on. Korra's setting is an aberration, because even though they have a more or less capitalist society in Republic City, it was founded by and overseen by feudal governments. It's sort of like the feudal version of social democracy. Republic City further reforms its way to independence and full capitalism during Korra (end of season 1 IIRC). TL;DR historical inertia (and continuing feudalism in the four nations) is the reason for the bending-based governments.
Yeah, he's basically idpol. Bending ability doesn't have a good parallel to real life though.
I thought this was more in line with idpolers tending to be "atoners" e.g. self-hating [insert identity here]. Comparing Amon to the USSR or any revolution that attempted to restructure society is being far too charitable to his character. As far as he was portrayed he had no plans for after all the benders were dead. Unlike Zaheer, there was never any suggestion that Amon's motivations went beyond his personal trauma. Zaheer, on the other hand, is repeatedly shown to have a plan for taking down the various world leaders. He's also implied to have a plan for what comes next, given the size of his organization. We never get details because Korra is too much of a hothead to listen to him, and he sees no point in explaining his plan to her since she's on his kill list.
There are certainly shades of this. This is what Korra's understanding is limited to, but she's pretty well established in-show to be an incompetent moron. I mentioned this with Zaheer above, but she refuses to consider the position of her enemies (unlike Aang, who did this to a fault) so we never get to know much of their plans. Of course, this allows for the show to have characters who could plausibly be genuine revolutionaries, but we'd never know because the protagonist (acting as a representative of the capitalist network) plugs her ears. The biggest support for this thesis is that Republic City spontaneously transitions to a democratic republic, and that King Wu decides to do the same to the Earth Kingdom. This is entirely predicated on fantastically benevolent leaders, which, of course is also support for that thesis.