I am deploying a small farm and am going to be using a taxonomy. Should I create a new Managed Metadata service application instance or just use the default? What are the advantages/disadvantages?
A new one should be created if you want certain web apps to have their own set of service apps. By grouping service apps you can allow for instance a web app to use the metadata service app and search but not the BCS by creating a new metadata and search service app and putting them in a new group and then assign the web app to that group.