Server 2008 Standard SP2: Group Policy for IE10

Hi there,

The server is currently running IE9.
To manage policy for IE10, we need to get the .admx file either by installing IE10 on each of the DC or manually copying the inetres.admx file from http://www.microsoft.com/en-us/download/details.aspx?id=36991

Questions:

1. do we need to restart the server after upgrading to IE10?
2. will the policy also covers the previous versions of IE?
3. is it worth it to create a central repository for ADMX?
   http://technet.microsoft.com/en-us/library/cc748955%28v=ws.10%29.aspx

Thank you for everyone's advice!