Block out days on Calendar / Auditing

I have a shared calendar (Room Mailbox) that we use to keep track of users PTO and WorkFromHome days. Is it possible to:
1) Get an audit trail of this calendar to see who has added or deleted events from this calendar?
2) Block out certain days and dont allow anybody to book PTO or WorkFromHome days (like on holidays)?
3) If we cannot block out certain days is possible to create an meeting for that days that does not show the meeting organizer in the meeting title.
Example; MLK Jr day: Company Closed