Just casue your domain doesn't exist, doesn't mean you still can't use your Apple ID of that name.
If you don't remember your password to it, you can always have AST help you reset this.
Account Security Team (AST)
Check the AppleCare number for your country here:
Call them up, and let them know you would like to be transferred to the Account Security Team.
In one of the help pages for managing your Apple ID (http://support.apple.com/kb/HE40), it shows two separate sections, one for Apple ID and one for Primary Email address. When I go to manage my Apple ID, I see only a single section for both. Can the two be 'separated', especially when you face the situation of having to discontinue your email address for some reason?
I also noticed that when navigating to Apple ID Support Communities, it shows my nickname 'dishdy'. How and when did I insert this? In the current sequence for creating an Apple ID I don't see this. In my current profile I don't see this.
In any case, I have freed myself from my previous Apple ID (@artemis.it) on my iPhone.
Thanks for your help.
You most likely inserted this when you set up your forum account. You are allowed a forum user-name, which hides your Apple ID. This is because some people consider it an invasion of privacy, as this is a public forum.
Also, along that lines, you MAY wish to continue corresponding with
iTunes Store Support
As you won't have to worry about the public seeing your Apple ID info in your posts being discussed. We don't want every spam-spider indexing your private information. Apple after all, doesn't follow Facebook/Google unethical practices.