iPhone - Difference between a Library UINavigationController and my subclassing UINavigationController

Answer 1

For your first question: Yes that does create an instance of a UINavigationController. You must then add a UINavigationController to the File's Owner class and link them with an IBOutlet.

IBOutlet UINavigationController *nav;

then in Interface Builder cntl+click on File's Owner, drag to the Nav Controller on the builder, release, and select nav.

For the rest of your question the issue is wether or not you need any control of UITabController.