I don't get why you think your question is unanswered. Your Apple ID is the central userid, and all else follows from it.
Try setting up your existing iCloud and me.com email addresses in another email client (as a test) with your current Apple ID password. It's almost certain to work, but you can't know without testing it.
The last thing I posted from Apple support states, in no uncertain terms, that your Apple ID password is your password everywhere. And I have done the best I can to explain how things might be set up such that what you already have set up using the old password might continue to work.
Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041
Always remember that computers are just glorified light bulbs - they rarely fail in continuous use and usually go pop when turned off and on.
~ Technician with the username Computer Bloke, on Technibble.com