While I suspect you are right on many points, I hope you are wrong. I want this series to succeed and be completed. I actually really enjoyed The Silver Chair and wish they would press forward in the proper order, especially since the actor who played Eustace will be significantly older when (if) they do get around to it.
As for Prince Caspian, I again state that it was my favorite of the films. I know it diverged from the book on many points, and the first time I saw it I was not that impressed. However the most recent watching pleased me more than I expected and I decided that in many ways I liked it better than The Lion, the Witch and the Wardrobe. There were some aspects I actually enjoyed about the film that were not in the book, particularly the competitive egos of Caspian and Peter.