I saw clips of Kyle kicking in a door and a guy holding a gun to Lindy's head. I saw the movie and that scene is nowhere in there. Is that an alternative ending?

I think that probably was an alternate ending. It would have been much closer to the book ending. That is probably also the scene that had the line "you are the most beautiful man I have ever met" (unless that line was in the movie and I missed it). There was also a scene in the preview with Kyle on the phone saying "I'll find you", which I'm guessing preceded him kicking down the door.

yes, thats the altered ending, the one i was hoping for but i still love the movie

sometimes they film stuff and put it out before they're actually done with the movie.