I think before you start doing any more merging of edges or vertices, you're going to need to clean up the model, just drag select around any one vertex then in the channel box click CV's (click to show) you'll find multiple cv's selected, not just 2 or 3 but 5 and 6. You need to start merging them together before you go much further. Even on the edge of the door if you drag around any cv you'll be selecting five.

As mike says as well, merging the cv's is an easier way to go. You'll also once you've got your cv problem fixed, start getting the geometery on the door and wing lined up a little better.

One other thing, when you fix the cv's you might want to run polygon cleanup as you have some bad topology going on in your model.