The questions range from general background information to in-depth technical issues.
An SRV record maps the name of a service to the DNS name of a server that offers that service.
A new feature in Windows 2008 is a new type of domain controller the Read-Only Domain Controller known as RODCs.
An RODC makes it possible for organizations to easily deploy a domain controller in scenarios where physical security cannot be guaranteed, such as branch office locations, or in scenarios where local storage of all domain passwords is considered a primary threat.
It is not a big deal to manipulate a Windows system if you can get physical access to it.
Since Domain controllers store security sensitive data, they are particularly endangered.