MS Bookings calendars

Get list of Bookings:

(Get-Mailbox -RecipientTypeDetails SchedulingMailbox -ResultSize:Unlimited).PrimarySmtpAddress

Get associated user(s) with Bookings calendar:

Get-Mailbox -RecipientTypeDetails SchedulingMailbox | Get-MailboxPermission | Select-Object Identity,User,AccessRights | Where-Object {($_.user -like '*@*')}

Remove Bookings address list from global address list (gal):

Set-Mailbox -Identity "BookingsEmailAddress" -HiddenFromAddressListsEnabled $True

Adding a user to a Booking as an Admin:

Add-MailboxPermission -Identity MyBooking@live.xxx.com -User joeUser@xxx.com -AccessRights FullAccess -InheritanceType All
Add-RecipientPermission -Identity MyBooking@live.xxx.com -Trustee joeUser@xxx.com -AccessRights SendAs -Confirm:$false