Yes. This has been available since the first versions of IIS. IIS 4 allows password control; IIS 1, IIS 2, and IIS 3 do not support password management.
The IUSR_machiname, or any account being used for anonymous access, must have Network Logon.
No. The client account cannot leave the Web server computer because a Windows subauthentication DLL is used to log on the account.
No. Anonymous will work with or without Active Directory.
All.
Yes.
Technically, this is not an authentication scheme.