Captain America would probably be very reflective. He might see his past self as a reminder of his long journey and how much he has changed. He could try to offer some words of wisdom to his younger self.
Goku's reaction could be a mix of shock and joy. On one hand, he has been on Earth for so long without any real family connection to his Saiyan side. When he sees his parents, it would be overwhelming. He would likely be in awe of his father, Bardock, given his father's reputation as a strong Saiyan. And he would be eager to bond with his mother, who he has never known. He might also feel a sense of belonging that he has been missing all his life.
Goku would probably be really confused. He loves Chi - Chi and their family, and he might not understand why Bulma would want to break them up. He might just tell Bulma straight that he's happy with his life as it is. Chi - Chi, on the other hand, would be furious. She's very protective of her family and her relationship with Goku, and she'd likely give Bulma a piece of her mind.
Some gods might be entertained. For instance, Hermes, being the trickster god, might enjoy seeing the different and often humorous takes on the gods in the fanfiction.
Again, without more details, it's hard to say. He might be very interested and listen attentively, nodding his head and asking questions throughout the story.
Since we don't know what the story is, it's difficult to predict Amir's exact reaction. But generally, if the story is engaging, he could be completely absorbed in it. He might interrupt Soraya to share his own related experiences or just listen intently and give his thoughts and comments after she finishes. He could also be inspired by the story and think about how it relates to his own life.
At first, Naruto would probably be excited. He's always eager to get stronger, so he might see this as an opportunity. He'd trust Tsunade because she's the Hokage and a respected medical ninja. But if the experiments got too painful or started to seem strange, he'd start to question things. He might try to talk to Tsunade about it, but in his Naruto - like way, still be respectful.
He could also be initially confused. Sasuke has known Sakura for a long time, and this unexpected act from her would leave him wondering about her motives. He may hold back his anger for a while to hear her out and understand why she did such a thing.
He would probably try to reason with the dwarves. Legolas is not one to jump into a fight immediately. He might try to explain that there is no need for such hostility and that elves and dwarves can resolve their differences in a more civilized way. If reasoning fails, he would then start to look for ways to break free from his bonds and overpower his captors using his elvish agility and archery skills.
Boruto might be in awe. He has always known his father as the Hokage, a powerful and respected figure. Seeing Naruto's past full of struggles, loneliness, and determination would make him realize how far his father has come. It could also make Boruto more empathetic towards Naruto and perhaps inspire him to be more like his father in some ways.