Oracle APPS is probably the stuff which gives more pain in the a** to any oracle consultant. Then we have the Oracle Application Server which can be quite a pain as well although the later versions are getting ok but the policy of changing things in OracleAS every 3 quarters doesnt seem quite a good move.

MBA is Business Administration. What kind of business is a DBA going to administaer...? May be can provide you good salary when you have decided stop being technical and forget about the Oracle World. But then again before that happens you must learn how business works. A DBA in fact is in a quite good position to learn business developments (personal experience).