Oh, please. Violence can often times be more nasty when it's off-screen. It's called letting the audience think for themselves. I don't care what franchise it is, if you're going to see it based on the gore, then it's not worth seeing. Whatever happened to having a good story and god acting?

And AFAIK the f-word in PG-13 is limited to one, non-sexual use (IE Catch Me If You Can).

Who cares what the rating is? Just see the movie. If it's bad, it will be bad on its own account, not by how much gore is in it.