No, it's not. Peter's whole story of power loss and Spider-Man no more is ripped from the comics in SM-2. Doc Ock has the comic book stamp all over him;
http://molinaock.blogspot.ie/
Harry seeing his dad's ghost telling him to avenge him and then finding the Goblin lair. Aunt May struggling to make ends meet. Peter struggling to hold down a job. All from the comics.
Exactly. MJ keeps giving Peter chances to be there for her and he keeps letting her down. She wants him to show that he can be there for her but he never does. Then when he comes to her and says he wants to be with her, she is afraid to trust him.
Also you never get the feeling they cannot stand being around each other. The only time there's an all out unpleasant scene between them is at the Planteterium, where MJ tells him everyone else from Aunt May to her useless father can show up to see her play, but her so called best friend can't.
That was one of the best scenes in the movie. The whole planeterium sequence I mean. First MJ rejects him, then Harry accosts him in a bitter drunken state and publicly slaps him. Then to add the final kick while he's down, MJ and John announce their engagement.
Just a high emotional sequence all around and Toby, Kirsten and James are fantastic in it. In true Raimi fashion the whole scene is not drenched in misery, because we get some of the light hearted moments from Jonah Jameson (great to see him out of the Bugle office), and Peter always missing the hor dourves on the trays.