Well, I can't answer your question about removing the starter.
As far as not starting correctly, I am having about the same problem in my Dakota (except my starter has not stayed on). I have not looked into the problem yet (I'm have a lot of other work to do on my truck, which I will do in August).
As far as the oil change, I have a post
(#25), and if you buy the correct oil (with a link in that post that shows you some oils that meet thest standards) that Cummins says you can do a 15,000 mile intervail, or 7,500 for the other grades of oils. Doing an oil change every 3,000 in the CTD is nothing more than a waste of your money, since these engines will live forever even if you extend the drain to 7,500.