Well, I finally figured it out.

They appear to talk about a Microsoft Account (MA) as though it were a God account, superior to everything else, and that one account is needed before you can manipulate the "lower" six (in my case) accounts.

It aint so. MA is nothing more than a category to which each of my six accounts must belong, which answers my basic question; however, there's a problem. At first glance, your email account can qualify as a MA if it already uses one of a select few domains. Offhand, I don't remember what the list is, but I know Outlook.com and Hotmail were two of them, and there were a couple of others. Unfortunately, my domain (live.com) could not become an MA, because live.com is a "reserved domain", whatever that means. If you try to make your account an MA, rest assured that if you're using a domain that's not on their list, they'll let you know in no uncertain terms.

I thought I was at a dead end, so I got some help from a Microsoft agent. By the time she was finished with me, my six live.com accounts were MAs, and I don't know how she did it. I didn't care, because I was now operational. I am curious though, and I should know how to do it, in the event that the situation comes up again. I drafted the question some time ago, but I've simply procrastinated sending it in. I will send it (one of these days) and I'll post the answer to this thread when I get it.