OK, Blogger has apparently given us the ability to transfer blogs between accounts. But is it safe?
I'll find out. I take one of my less valuable blogs, Miscellaneous Musings, as my guinea pig.
The blog has but one administrator. There's no "Remove" link, and "Admin" isn't clickable.
I invited my second account, as a blog member. Note that you can invite anybody, GMail or any other email address. The invitee can use any existing Google account, or setup a new Google account, at his convenience. Any new account can be based on a GMail address, or any other email address. The invitee should take care to make that account, and email address, safe and secure.
I accepted from the second account. Note that only the second account has any clickable links.
Both accounts are now administrators. Either account can be removed ("Remove" is clickable), or made Guest ("Admin" is clickable).
I clicked on the "Remove" link from my primary account. Now, the secondary account only is administrator. Note, again, "Admin" isn't clickable, nor is there a "Remove" link.
I reinvited my primary account to be a blog member.
The primary account is still a Guest. Still no "Remove" link for the secondary account, which is the current administrator.
Now, both accounts are administrators again.
And once again the primary account is the only administrator.
OK, it looks like it works. Now, a canonical procedure for everybody to follow.