Todo GPO é "forçado".
A resposta para 1 a 3 é um sonoro NÃO.
Nesse caso, peço que criem usuários para os serviços do SQL Server. Esses usuários devem ser adicionados ao grupo que pode ser executado como um serviço e, em seguida, configurar a máquina SQL local para execução usando essas credenciais.
A Microsoft tem um guia de ameaças e contramedidas. Procure. Eu vou colá-lo aqui. Estou no celular, então me perdoe por não formatá-lo corretamente.
Log on as a service
This policy setting determines which service accounts can register a process as a service. In Windows Server 2008 R2 and Windows 7, only the Network Service account has this right by default. Any service that runs under a separate user account must be assigned this user right.
Possible values: User-defined list of accounts / Not Defined Vulnerability
Vulnerability: Log on as a service allows accounts to start network services or services that run continuously on a computer, even when no one is logged on to the console. The risk is reduced by the fact that only users with administrative privileges can install and configure services. An attacker who has already attained that level of access could configure the service to run with the Local System account.
Countermeasure: By definition, the Network Service account has the Log on as a service user right. This right is not granted through the Group Policy setting. You should minimize the number of other accounts that are granted this user right.
Potential impact: On most computers, restricting the Log on as a service user right to the Local System, Local Service, and Network Service built-in accounts is the default configuration, and there is no negative impact. However, if you have installed optional components such as ASP.NET or IIS, you may need to assign the Log on as a service user right to additional accounts that are required by those components. IIS requires that this user right be explicitly granted to the ASPNET user account.