Question: Do Guests need an Office 365 subscription for the Office 365 viewer?
Answer: No, Guests only need an Office 365 subscription for editing personal copies.
Question: Does anybody but myself see my personal copy?
Answer: No, a personal copy is strictly personal.
Question: Can users see other user names through the Office 365 viewer?
Answer: No, a personal copy is strictly personal.
Question: Can I see what changes I made in my personal copy?
Answer: No, track changes is not an Excel functionality.
Question: What happens to my personal copy when the original gets deleted?
Answer: The personal copy is a working copy of the original file, the access to this copy is a 1-on-1 link to the access to the original file. In case the original file gets deleted, the personal copies will be deleted as well.
Question: If a deleted file gets restored from the recycle bin, does a personal copy gets restored as well?
Answer: Your personal copy is a copy of the restored file, so it will reappear.
Question: What happens to my personal copy when permission on the original file is taken away?
Answer: Your personal copy will be not visible as well.
Question: What happens to my personal copy when permission on the original file is granted again?
Answer: Next to the original file, your personal copy will visible again.
Question: Can users see on which documents they have created a personal copy?
Answer: Yes, the indication sign in the index shows the presence of their personal copy.