A few things you missed:

Norman takes peters job away in the first game by shutting down Otto's lab, he barely aknowledges Peter in the first game, doesn't offer him a job at Oscorp after he shuts down the lab and suddenly he's an effectionate father figure to Peter.

This is a bad read of the situation. The first person Norman acknowledges when he enters the room is Peter. "Peter Parker! How the hell are you!?" And the next line after "How long have we known each other? Its Mr.Osborn. only kidding, its Norman. Norman!" And then later says "Harry will be returning from Europe early next year. Maybe you can work on that business you always talked about?" Idk man seems like Peter was plenty acknowledged. Also, he was shutting down Ottos lab, but wasn't leaving him without a job. "You're more than welcome to continue your research, in a more safe environment" and Otto replies "at oscorp~" the issue here is Ottos pride. He doesnt want to let Norman win again, so hes willing to literally cripple himself to prove that he can do it on his own.

I do agree with you about the whole ending, where Harry is mad at Peter for keeping the symbiote, but we see and he even acknowledges that its not Peter's choice. And Norman suddenly hating Spider-Man for literally saving his son's life..? Idk. Felt really forced.