I have never done the cleric epic, but have you looked at the Wiki guide here for it?
http://wiki.project1999.org/Cleric_Epic_Quest
Will probably answer a lot of those questions. Otherwise the only fights I know of that require any real force is the BW and Ragefire.
edit: Sorry and Overking in Chardok. Don't think much else requires any real force. Should be able to start at 46-50.