I need to install PDF server app on a separate machine from my index server/master license server
1) the PDF server app requires that you have an Enterprise license installed, and it also requires Python, so it will not run on the universal forwarder.
2) you can use the CLI commands described here (the Add command in particular) to install and configure the license behavior of your heavy forwarder:
http://www.splunk.com/base/Documentation/latest/Admin/LicenserCLIcommands