Need to add environments for EPM Enterprise Edition

Summary:

We are getting ready to setup the EPM Enterprise Edition for a new project. We need to setup three environments ( dev, test and prod ) with the possibility of adding one more environment. Based on the Oracle doc, it appears we can only have two environments ( test and prod ). With that said, how can we request for a "dev" environment ? Is there an additional cost to request for an additional environment like "dev" ?

Can we have dev, test and prod environments share the same account name ( or domain name ) ? We chose to create a new account as opposed to using an existing account. Can we add "dev" to the instance name for dev environment and "test" for test environment ? We would like to make the instance name reflect the correct environment so it won't be very confusing.