The WWI-steampunk-era setting is interesting, but it just seems to serve as a centralized backdrop that really shutters out the entire rest of the world. Initially the things with Amon were really interesting, but I kinda lost any sense of him being a threat more than just being a plot device.
Tarrlok being his brother but not working in tandem with him intentionally seemed like a BIG stretch, especially since they had a clear connection in their past, and the actions of one always directly fueled the reactions of the other, and I totally didn't buy the, "we became just what our dead dad made us into" at all.
When Amon attacks the pro bending match, I can totally believe that the shock gauntlet people tool out the police in their metal uniforms, but it's hard to believe that there weren't ANY other benders in the stands that would try to fight back. Republic City seems to have a weird sense of how many benders are/aren't in any location at a given time. In ATLA, they always managed to find benders in certain locations to assist them in doing things, but in Korra, they've only really been there as set pieces, and haven't really shown themselves in any capacity aside from being rounded up and eliminated.
Also, Korra learning Air Bending felt like it was treated like Indiana Jones working on Teaching Material. It was just there when it needed to be, and it's talked about as something that occupies time, but it never really seems like it past the very start of things. It really fails the "show don't tell" I mean, even having her running through forms or something for a few seconds in her spare time would've worked, but instead her air bending just seems to emerge through the Deus Ex Machina moment that it needed to.
Speaking of which - The final confrontation with Amon was dick-rippingly frustrating. Mako just tosses him into a pile of boards (and doesn't finish him off), and then they throw the water bender into the fucking ocean (which DID serve to oust him to the public, but was still a fucking stupid idea). Also, there's no explanation for how he managed to capture the Air Bender family other than plot devicing. Also, of the hordes of people that have faced off against him, it really just seemed like they were able to beat him because it was the end of the season, and not because of any REAL development - especially because he's beaten better Air Bender amily, and Korra just manages to pull that out at the last second.
Also, when she did get her bending taken away, I wasn't even REMOTELY concerned because the construction of other people getting it taken before made it obvious that it was gonna get Ctrl+Z'd away relatively soon.
Aaaaaand, aside from Bolin's initial crush on Korra getting knocked down, I think that the whole love triangle nonsense is all really dumb and a waste of time. Here's to hoping for better progression with that sort of shit later on.
tl;dr - If I'm headed into a world of pain, I'm excited because hopefully that means that it'll actually have stakes that I find believable/engaging.