Stuck on Rod of Keretoc quest. (SPOILERS)

Please!? Send me a hint! I know it has something to do with casting elemental spells at the secret doors - throw a player a bone! I can ALMOST see 2 symbols of gods in the floor, where ...something should happen. They look like Typhis and Conflagral, respectively ...and then one spot behind the throne that LOOKS like it should have a clue...but just looks like it should - it doesn't seem to give anything away.

The statues in the main hall seem to give a vague hint at "rocks coming up from the ground" and "calling the storm:

Also, there's one door that's locked and doesn't talk (just past the "Fireball" door...Intentional or broken? Should I keep looking for a key?

Good long dungeon...in desperate need of a clue, please.
Thanks!

That quest has a bug (or two)...I'm still trying to figure out the exact cause.

I've given myself 4 more days to test out fixes before I re-script that entire quest from scratch.