CLM Data Warehouse Oracle - why .ora instead of .dbf files

1. Is there a way to customize the data warehouse creation scripts so that the data files can be in one directory and the index files are in another?  The customer uses multiple mount points / directories for the databases and has data files in one directory and index files in another (hope I explained that properly).
   
2. Once I ran the create tables step for the data warehouse, the DBA noticed that there were some .ora files that were created.  I saw in the article below where those can be created manually, the locations can be changed but that the names of the files cannot be changed.  I presume that includes changing the extension as well.  Can someone please let me know why it creates .ora files versus .dbf files.  My apologies if the answer is simple but I'm not a DBA or even close to pretending to be one.  The DBA would like to know if it can use .dbf files versus .ora files.
   

https://jazz.net/wiki/bin/view/Main/MoreControlOverTheOracleDataWarehouseSetup

Thanks so much

Mike