The insurance plan and the warranty should cover your phone for 2 years. So if anything happens call up your apple store or your cell phone shop and get them to fix it. If they say they can't just start complaining and say you will switch cervices. They are trained to cave fairly easy to keep customers.
The last time I purchased it was one policy per phone. Lots of fine print. Soak that phone and you pay. Love to hear if that's changed. My kid has had 4 new phones! Due to odd little problems mines been perfect so it was worth it to us. You decide.