Well, they tried really hard to paint Kuvira in a bad light in this one. Unfortunately you can't really rush that sort of thing, so characters repeatedly accusing her of being a tyrannical dictator just came off as them throwing a tantrum. We saw that she helps the small communities, works hard to unite a broken nation and the people love her. Yes, she didn't exactly play fair with the governor that one time, but who said his opinion was the right one?
Even if she just wanted so seize power from the start... she's capable, hard working and, again, the people love her. She's still so far ahead of that airheaded political puppet Wu it's not even funny. How on earth are we supposed to buy into her being evil if the alternative is that fucking awful?
Bolin on the other hand is a bit too easy to convince. "Haha all that part about me becoming Emperor Palpatine and crushing my enemies? Just tough rhetoric *wink wink* I'm really nice here have some cholocate" I always thought of Bolin as kind of an infant so maybe this is the time for him to fall on his face and grow out of it.
I like that Toph still was Toph after all this time and she kinda had a reason to live in the swamp. Bit puzzled about the "tiny bits of metal" explanation for Korra's condition, though. There must be more to it, otherwise that vision doesn't really make sense. Hope we get a better reason in the next episode.