Symantec Appliance 5230 master role

I have an inquiry about pros and cons of having a separate physical server as master server against making the 5230 appliance have the 2 roles "master,media"

what i can think of is to take headache of scheduling from the appliance plus having second point of failure that can communicate with the tape library in case of appliance outage for any reason ..

Second question : can i add new capacity based license for the appliance besides existing old license that's on the old master server