No. This will cause the VMM server to malfunction. However, you can install the VMM server on a computer that is already a domain controller.

Yes. If you are using a disjointed namespace, which occurs when one or more computers have a primary Domain Name System (DNS) suffix does not match the DNS name of the Active Directory Domain Services (AD DS) domain of which the computers are members. For example, a member computer that uses a primary DNS suffix of corp.fabrikam.com in an AD domain named na.corp.fabrikam.com is using a disjointed namespace. For more information about a disjointed namespace, see Naming conventions in Active Directory for computers, domains, sites, and OUs (http://go.microsoft.com/fwlink/?LinkId=123886). For more information about installing VMM in a disjointed namespace, see Planning for a Disjointed Namespace.

No. Instead, you can run VMM on a highly available virtual machine. For more information, see Planning for High Availability.