Hi,
the first questions is related to the Exchange Room Mailbox associated to the Teams device.
To obtain it you have to set the "ProcessExternalMeetingMessages" setting to True with the following command.
Set-CalendarProcessing <RoomMailboxUPN> -ProcessExternalMeetingMessages $True
Docs Reference: https://learn.microsoft.com/en-us/powershell/module/exchange/set-calendarprocessing?view=exchange-ps
The second question is not clear, could you explain it bettere, plese?
Best Regards
Luca