I finally finished the game and here are some tips that may come in helpful. If you have a party member that refuses to go in to an area, just run your group around for a while until that member goes uncontious then walk in to the area.
I made the mistake of not having anyone who could cast silence and when I got to the sorceress temple it was very difficult. As you first approach the temple walk very slowly towards the opening. As soon as you notice one of the death knights, begin to move your group slowly back. If you time it just right, the death knight will follow you outside of the temple without engaging the others. Kill the death knight and then try to draw out the other one.
I skipped a lot of areas entirely and went to the Trynnie's early in the game. Then after killing the Don, I went to Rapax rift. This is a great place to earn XP fighting all of the rapax.
After I cleared out the rift I went to the sea caves to get the destinae dominus but I didn't have the helm of serenity so after I killed marten's ghost all of my characters went insane.
Fortunately, I have already cleared out Rapax castle, so I walked back to the casle with all of my characters insane and manged to put the destinate dominius on the pedestal. After a fest castings of make sane everyone was back to normal.