Oracle DBA Role and its specific functions

I want to install an application server that requires an user to write to the database, possibly create new schemes and such. However, I've always used the "work around" to assign the Oracle DBA Role to that user.

I have some questions, as I am not that deep into Oracle security.

  1. Has the Oracle DBA role a level of privileges that can affect the whole Oracle installation?
  2. Where can I find what privileges the DBA role exactly have?
  3. How do I create an alternative role?