Oh yeah I sooo agree with what you're saying, it really did feel like Katara was just angry at Zuko for no reason now, she wanted to hate him but he kept giving her reasons not to and that was frustrating her even more, plus she already trusted him and was comfortable around him b/c she would get so close to him and be up in his face, she wanted him to slip but he never did and that drove her crazy, I think she should've forgave him sooner like after he saved Hakoda, what do you think?
You’re right that she already trusted him. She had to and here’s even more examples beyond her body language:
1) She let him be alone with Aang.
2) She let him travel with Aang to an undisclosed location for an undisclosed amount of time.
3) She didn’t seem to be freaking out when he ran off with Sokka for however many days that was.
4) After he saved her dad, it did seem that she tolerated him. I think being forced to separate from her father when Azula attacked triggered her rage again (another family member gone because of the Fire Nation) and she directed it at him.
She knew he’d changed. She knew he wasn’t going to hurt herself or her friends. She did trust him. She just found it easier to project her feelings of hatred on him than rage against an entire nation. She couldn’t hurt the Fire Nation for what they’d done, but she could hurt him. She was constantly snapping at him and pushing him to a point where any normal person would explode, but he remained patient, just proving her hatred wrong even more.
As far as when she should’ve forgave him, I think it came at the proper time. The fury we saw in The Western Air Temple wasn’t just going to disappear… it was a lot deeper than hurt feelings and anger. It was malevolent. It was burning her up from the inside out. Saving her dad wouldn’t fix that kind of deep-seated rage. They needed to be alone and discuss what was wrong. Katara needed to explore her relationship with him, not her relationship him and her friends.