

The Essentials features are still configurable with an answer file, and that remains using the CFG.ini file. This means for an unattend installation of the Server OS, you need to use standard unattend methods as discussed here: Unlike SBS 2011 Essentials, Essetials 2012 installation uses the same code base as standard server 2012. Unlike prior versions you no longer need an answer file and can enter migration mode via the GUI.

Official SBS Blog: Running DHCP Server on SBS 2011 Essentials With a Static IP. When installing the DHCP role, ensure that the other DHCP servers are turned OFF before you install the role.

Is assumed that DHCP will be enabled and running on the router as you build the WSE12 server. Whilst you can install the role later after the server is installed and assign the server a static IP, it The assumption is that the external router will perform the role of DHCP and provide WSE12 with a dynamic IP address. Note this does not mean it has to be the only DC, just that like the products it inherited it's legacy from, that The assumption for Windows Server 2012 Essentials (hereinafter called WSE12) is that it will be the first domain controller in the network.
