16. Do you think Zuko and Katara developed feelings for each other in canon or post-canon?
I think, Zutara developed feelings for each other in both canon and post-canon.
If talk about development feelings in general and not specifically about romantic feelings, I can say that their development feelings had been there since the beginning of the season.
When they first met, neither of them cared about each other's existence. Zuko didn't see Katara as a threat, while Katara only saw Zuko as someone from the Fire Nation. They were enemies, nothing more than that.
After they met a few times, Zuko's impression of Katara changed from an unimportant girl and terrible waterbender, to an enemy that couldn't be underestimated.
It's a development of the relationship.
Then, their conversation in the Crystal Catacomb became a significant development in their relationship.
Their feelings develop from enemies, to someone who can understand each other because they have the same experience, which is losing their mother.
Katara trusted Zuko enough to give him something she was saving for a very important situation. Meanwhile Zuko trusted Katara enough to let her touch his scar.
Katara's expression towards Zuko conveys different meanings, in the first scene she looked annoyed and in the second scene she looked hurt. It showed that after Zuko betrayed her, Katara's feelings for Zuko grew from hatred for an enemy to hatred for being betrayed.
No one would hurt when betrayed by an enemy, unless they already trusted their enemy on different level.
Their relationship development changed drastically after Katara forgave Zuko. Their feelings for each other changed from enemies to friends. And they became yin and yang, opposites but complementing and trusting each other.
When it comes to developing feelings romantically, I feel like the spark was there since their journey in Southern Raider. Moreover, I always had a headcanon that Zuko and Katara had a really deep moment together, until Zuko picked up the rest of the Gaang to Ember Island.
The spark was still so small, they could still deny it.
The spark grew bigger when they saved each other's lives when facing Azula. This moment makes a lot more sense if they were the ones kissing in the final scene.
Or if you follow the canon storyline, then their feelings would develop in post-canon, when they finally realised that their 'canon' partner wasn't a bad person, but not right for them. They could no longer deny their feelings for each other and end up together.
17. How do you think Iroh and Hakoda would react to Zutara?
Iroh and Hakoda are wise men, I feel like they wouldn't have a problem with Zuko and Katara's relationship.
First, Hakoda. He initially had a bad assumption of the Fire Nation royal family until Sokka said that Zuko could be trusted. And Zuko proved it by reuniting him with his daughter.
Not only that, Hakoda must saw when Zuko saved Katara from the rocks. Hakoda certainly could trust his daughter's safety to Zuko no matter what the stakes. And that was proven when he gave up his life to save Katara from Azula's lightning.
If they were together, Hakoda clearly had no worries about his daughter.
In post-canon, Katara couldn't deny her feelings for Zuko but she was hesitant. She thought about her mother who died because of the Fire Nation, how she ends up in a relationship with the Fire Lord?
Hakoda would convince Katara that Fire Lord Zuko wasn't the one who killed her mother, instead he was the one who brought her to her mother killer. And her mother wouldn't be happy to see her daughter kill her own heart because of her, after she sacrificed her life to keep her daughter alive.
Then Iroh. He knew his nephew very well, especially his stubborn nature. Iroh is wise and always sees things from a different perspective, he must felt that Katara was a good influence on Zuko. But still, I'm sure he was surprised when Zuko, without any hesitation, asked Katara to accompany him to facing Azula, rather than insisting on fighting her alone.
If they were together, Iroh must be sure they would complement each other, because he knew there was bond between them since Zuko took the lightening to save her.
In post-canon, Zuko couldn't deny his feelings for Katara but he was hesitant. As a Fire Lord, he was afraid that his people would not accept someone from the water tribe to become First Lady. Moreover, this had never happened before in the history of the Fire Nation royal family.
Iroh will convince Zuko that he has made history by declaring the end of the 100-year war, he as Fire Lord can also make history by marrying someone from the Water Tribe. Their marriage will be a symbol of peace between the Fire Nation and the other nations. Also, Zuko has a lot of responsibilities and Katara could help him to lead their people.
18. How do you think the Gaang would react to Zutara?
When Zuko and Katara surprised the Gaang that they were dating, no one shocked, except for Aang.
They were like, "I knew this day would come."
Zuko and Katara didn't realised that their love on each other was very obvious. The rest of the Gaang knew it from the start, but kept it quiet and gave them a chance to develop their own relationship.
I guess, the Gaang started to get suspicious at this point. They didn't know what their problems, but it seemed very personal.
Imagine after that, Zuko went to Sokka and talked about his sister. Since Zuko interrupted his date with Suki, Sokka must've told her and Suki started to wonder, "Is there something between them?"
After a little field trip with Zuko, they seemed to be very close, but they denied it. But, the more they denied it, the more it became clear there was something between them.
It was weird that during the performance of Ember Island Players, the Gaang always commented on various occasions, but they didn't comment or shocked during Zuko and Katara scene in the Crystal Catacomb.
I mean, the show did exaggerate the facts, but it was still based on reality. No one really knows what was going on between them and the scenes on stage were supposed to be controversial.
I was expecting a comment, maybe from Sokka as her brother, like, "Hey, you guys weren't really flirting, were you?" But no, Suki smiled instead and Sokka looked like it wasn't a surprise.
They denied it again when June teased that they were dating. Did the Gaang notice? Of course!
They held hands before, then they slept back to back, then Katara comforted Zuko before meeting his uncle, then Zuko asked Katara without hesitation to face Azula. And Gaang was there to notice all of that.
As I said before, all of the Gaang members are aware that there is something between Zuko and Katara, except Aang.
It wasn't like Aang didn't realise that, he just denied it because his attraction to Katara. He was still saw her as his 'forever girl'. But later, after Aang matured, he finally realised that his duty as the Avatar was far more important than his crush on Katara. The only way to open his chakra was to let Katara go and he did that.
Aang finally accepted the relationship between Zuko and Katara.