You can delete VMs from your own profile. I posted (partial) directions here. Do you need a more detailed version?

When you delete a VM yourself, or when a moderator deletes it, you'll see a "This message has been deleted by..." marker. Only you, the moderators, and the administrators can see those on your profile; to other members it's as if the VM had never been there. If those markers really bothered you, an admin (but not a mod) could remove them for you.

I don't know the answer but I'm guessing they're displayed in random order on purpose. That way, if you have more friends than can be shown at one time, you (and your profile visitors) won't always see the same ones while the same other ones always remain hidden. I don't visit my own profile that often and when I do, it's kind of fun to get reminded of friends from when I was new here, that I may not have heard from in years.