Client

• Monitors
  
  • Please see the following wiki article for more information about maximum monitor resolutions:

    http://social.technet.microsoft.com/wiki/contents/articles/31983.remote-desktop-protocol-maximum-supported-resolutions.aspx

• Remote Desktop Licensing Server
  
  • No hard limits as far as the number of CALs that can be entered.  Have heard of one RD Licensing Server that had 70,000 CALs entered on it.
• AD
  • RDS in Windows Server 2012 does require Active Directory.  The schema should be Windows Server 2008 or above.