(1) DP 7 Supports Windows 2012 R2 on physical and virtual Servers. Suggest to havve Patchbundle 7.03 and following Patches installed for full support
(2 & 4) Download the Install-Image from HP Support-Page, execute the Setup on the Target machine and follow the wizard. To Backup a System you will only need the Client-Installation and the Disk Agent Component selected
You can also install the DP InstallationServer on a Machine and use Push-Installation in DP-GUI to install and upgrade the Clients if you like.
(3) SQL 2008 R2 with Win 2012 R2 is not supported under DP7 as far as I know (please anybody correct me on that if wrong)
Suggest to consult the Integration Guide for Microsoft Products for the Configuration steps.