4. Kill John Hammond
Despite the fact that John Hammond is played by the much loved Richard Attenborough, and isn't portrayed (on screen at least) as a particularly bad man, he
is still the man ultimately responsible for the creation of the dinosaurs and is therefore responsible for the countless deaths in the previous films and deserves his comeuppance. Whether or not it is done on screen or simply referred to (since I'm not sure Attenborough will be up to acting in a feature film any more), Hammond's legacy needs to end with him being killed by his creations - just like the greedier, more ruthless novel version was in the original Michael Crichton classic. I think it would make for a fitting end to the Jurassic Park saga and, given the more pleasant, family-oriented nature of the movie version of the character, a shocking twist that would make for a good story with potentially interesting repercussions.