No this is people who have registered john.johnson.name, but johnson.name remains Verisign's (and e.g. unrelated Alice has also registered alice.johnson.name)

Which is an insane scheme to begin with. Why not "john-johnson.name"?

So that you could use [email protected] as your email instead of [email protected]. The .name gtld was created in the height of the "we will move to a paperless world and email will become the universal way to communicate" era.

I just own lastname.com so my email is [email protected], would recommend (I guess probably a bit harder nowadays)

Only one person with a given lastname can do that (or I suppose one person and their near family).

Because registration of second level domains in .name was not available.

I don't think so. If you own it, you can have any subdomain.

At least I hope this is the case. I have a memorial page for my uncle under hisfirstname.ourlastname.name