Windows 2012 RDS CALs - OLP NL downgrade to Windows 2003 TS CALs

Hi,

Hope someone can shed some light on this inquiry

I plans to purchase the following:

 2x Windows 2014 SQL STD 2 Core License OLP NL
 30 Windows 2012 RDS CALs (User or Device) OLP NL
           Breakdown example
            Site A = 10 
            Site B = 5
            Site C = 15
 
Existing servers are Windows 2003 R2 STD running Terminal Services

Tried setting up a Windows 2003 R2 TS Server and install TS Roles & Licensing Manager

Questions.

 1. When I tried to add Windows 2003 TS CALs - OLP NL, the activation screen requires to enter the Authorization & License numbers.
 Can I use the Authorization and License number of the newly purchased Windows 2012 RDS CALs on the Windows 2003 TS Server?

 2. Should I get a separate Authorization & License number per site? (In the example above 3x Authorization & License numbers). Or can we use a single Authorization & License number for all sites? Each site is independent from each other.

 3. As I understand, SQL 2014 can be downgraded to any prior previous version at the same editions. (as far as SQL 2000, provided he has the installer), If client has an existing SQL 2003 STD activated already, does he need to change the license key?

Thanks,
Paul