I felt much the same, the idea that Hulk got scared. And we’ve already seen Hulk develop increasing language skills and personality.

Reading your analysis, it got me thinking & wondering just what Marvel would be willing to incorporate from the comics. If Banner’s childhood mirrors the comics, we’re looking at a history of a violently abusive father. Thanos could be providing quite a father figure flashback if that’s the case... but in the end it could be key to unleashing rage unlike any we’ve seen from the Hulk!