1. Jonah- Do not recast J.J.! J.K. Simmons is perfect for the role. His voice, his mannerisms, the look it's like Jonah leapt off the page. J.K. was made for the role; he was concieved onto this Earth to play him.
2. The suit. It's damn perfect. I could maybe see Spidey starting out with the webbing under his armpits like "Spectacular Spider-Man" but I would then want to see a progression.
3. I liked Rosemary Harris' Aunt May. She provided comfort, wisdom, love, sincerity, and also reacted the way Aunt May would given a situation she was put in. Maybe the Ultimate-version makes her hipper and less little old granny-like but keep all of what made Harris' Aunt May. Not saying you have to keep Rosemary Harris as her but just keep what worked about her.
4. Well, obviously the origin story. Told in either the opening credits or 10-15 minutes into the movie and then move onto Peter Parker/Spider-Man now at school, with his newly discovered gifts, still avoiding bullies and trying to win a hot date with the girls at his school, and being Harry's pal.
5. Music. The mix of Danny Elfman's orchestral theme and alternative rock/indy-sound on the soundtracks made each film work on it's own.
Changes:
1. Tell us what happened to Pete's family.
2. Show Norman as a smarmy, shadowy character. Keep his connections to the mob and people tightly-knit until he's finally exposed at movie's end. Disgraced and humiliated, that's when he decides to become GG and get his revenge not only on the board but on Tombstone or Kingpin.
3. Set up Adrian Toomes and Dr. Otto Octavius as lab partners working for Osborne. Have them first as cameos and then build their arcs through the movies. Maybe due to Oscorp having to shut down, Toomes finds out that his blueprints for a glider were stolen from him, and thus seeks revenge on Osborne, whereas Otto moves onto work in his own lab, but due to a radiation leak, the lab explodes, and infuses his harness onto his body.
4. Curt Connors and Peter's relationship. Let this grow and expand.
5. Daily Bugle. Give us more of Robbie Robertson, Betty Brant, Ed Needs, or other Bugle people.
6. Lastly, Gwen first, MJ second. I'd have MJ show up at either movie 1's end to complicate things or in movie 2 to get Pete to decide whom he really loves. Maybe Black Cat? Pete's got alot of women to juggle.