Oracle Database Discussions

We're renewing our Oracle Database 11g support contract right now and I'm being asked a few things since the Oracle quote is broken down into several sections. I don't know if I can use Oracle 11g R2 w/o OLAP. Can someone tell me if I'm correct in understanding the following URL:

http://www.oracle.com/technetwork/database/options/olap/index.html

According to the link, OLAP is only an analytics engine for the database, right? Is it bad if I remove support for this assuming we don't use / need it. I don't know what parts of the database software are essential to use rdbms functionality and which parts are simply optional based on usage.

Also am I correct in understanding that if I have two identical servers running the same 11g R2 software, in order to do replication or clustering of the same single SID / database, I would use RAC for this, right?