No worries.
Definitely agree with buffing Eeblis. If you have enough HP to take one blow from him, you're already half-way to beating him. Alternatively the map itself should be made more difficult, but excluding completely unwinnable situations like my previous example, I'm not really sure how that would be feasible.
Oh, regarding the shifting passages, the Transmuter is another easy class for it, even without Rock Heart. Then again I suppose the Transmuter is geared towards these sorts of maps.