I could see metalbenders being able to magnetize metal, analogously to how a waterbender can instantly freeze water. It's just a matter of altering the molecular structure -- in the case of making ice, organizing the molecules into a crystal lattice, and in the case of magnetizing metal, aligning the molecules' magnetic moments in the same direction.
Hey, remember last season when Varrick invented a magnet suit? And now Varrick is working with Kuvira. Maybe she studied his work and devised magnetization as a new metalbending move.
Anyway, Kuvira's battle tactics were awesome. She overcame those bandits with remarkable ease, and without excess violence, efficiently blinding and hobbling them so that she didn't need to beat or kill anyone. Which suggests she really wants to be benevolent -- but she's definitely convinced that her benevolence requires everyone else's obedience, that reuniting the Earth Kingdom under her leadership is necessary for the greater good of everyone in it. There's some nice ambiguity there. Although I'd say it's highly likely that the bandit who stole the food from Opal and Kai was working for Kuvira, given how his acts played right into her agenda. I was surprised we didn't get a tag scene revealing that.
So basically the EK has a choice between a well-intentioned authoritarian extremist and a dissolute, shallow boy king. Either one of which would be pretty much like going back to the way things used to be (cf. Long Feng and Earth King Kuei), and both of which would perpetuate old problems. Will Prince Wu grow into a better leader under Mako's guidance? Will Kuvira reform and become a better leader? Is there a third option, like democracy? Will Mako and Bolin end up running the EK?
Meanwhile, now we see why Korra cut her hair -- to go incognito. She's kinda back where she began, competing in sports arenas, only she's let her skills deteriorate, it seems. Or maybe she's losing on purpose so as not to call attention to herself. Anyway, it's so in character for her to make a living as a fighter. And it's a logical outgrowth of where she was in the last season's finale. I could tell that she felt she wasn't needed or useful anymore.
I guess that clip we saw earlier of long-haired Korra sailing for the south to recuperate will be in a flashback. Hopefully Chapter 2 will fill in the events of the past 3 years.
I was just struck by the irony: This is the largest in-story time gap between consecutive seasons of a single Avatarverse series, and yet it's the shortest gap between the release of two consecutive seasons. (The gap between Books 1 & 2 was six months, while only two weeks elapsed between Books 2 & 3.)
I really like the new Air Nomad outfits. That's very clever the way the wing membranes snap onto the collar and belt. I'm not convinced they could really be furled or unfurled quite as quickly as shown, though, since snaps can take some fiddling to get into place.
By the way, I never realized until now that President Raiko is voiced by Spencer Garrett, aka Simon Tarses from ST:TNG's "The Drumhead." He always sounded like Richard Epcar to me, so I just assumed that was who it was.