Icloud is good but not perfect

Icloud is great when it comes to backing up your data, apps, contacts, and everything else but it falls short with creating a unified experience. When setting up your iphone you have to use an apple id to activate it. When you set up icloud you can create an email address. The only problem is that email address can not be changed into your apple id as of now. Which means you are held to that your apple id that is connected to your phone and an apple email account which you can have mail on. If you want to use apples mail client you have to use another email to purchase apps and hold all your data. This is the complete opposite of the great user experience apple strives to generate with it's devices. The only answer to this would be to use another email for both apple id and email but the only problem is you don't get the same great push mail and syncing that you get with the apple email.