1) Meh, You're a good writer.
2) eh, I'm fine with that, I just don't want to see either tarnished by a string of bad sequels made to cash in on the franchise. (Imagine Star Wars, since everyone hates those prequels except me... )
4) Of course it sells. Few people buy those straight to video disney sequels and mary kate & Ashley movies, but no matter how much crap it is, it's marketable.
Now, I'm not saying that they couldn't do another movie in the Jurassic Park universe, I'm just strongly against rehashing the "people go to island, die, escape" theme they've pretty much used for the past three movies.