I think there is a navigation item property you can set that turns the back button off.
As for changing the cells and headings look at the table view documentation. It can get kind of tricky when doing weird stuff like that and the order you are supposed to remove cells and sections in isn't well documented. The best resource I might point you at is a thread where I and someone else discussed how we were doing it:
viewtopic.php?f=7&t=368
The best thing I found to do was change around the order I added cells/sections in until it animated properly.