There are a lot more internal dialogue scenes like that though. He also does have moments where he tries to reach out to other characters like Zell and Selphie after they both suffer from bad moments. He actually does try to reach out to people from time to time but he does it in an awkward way and when people wonder what he's doing he backs away in fear but he actually tries.

Regarding the Missile Base reunion. Even if you bring Rinoa with you, you get a scene where he actually mentions he was worried about their safety and Rinoa questions him about his real feelings about his teammates and her. I feel you're too hung up on what you felt was a drastic change (and its not as uncommon as you think ) and ignoring a lot of the build-up cause Squall doesn't try to be happy or funny and instead is just awkward and bit aloof. Basically you ignore his attempts cause its not how you felt it should be done.

You also miss the point of why I felt the dance scene is important. Yes it does cement why he thinks like he does but it also shows he can be open and fun if he wants to be and just let's go of his mental baggage.

Also, Amarant is a terrible character, with no real growth. He's an ass, reveals he's got a stupid reason to be an ass to you, and then never leaves your party and remains an ass. There was no growth with him imo. But I digress, this is not important to this discussion at hand.