Suggestions to "spice" up the quest:
Hidden Door with good DC for Rogue/Arti to find to bypass one of the locked doors. You can add some spiders or traps in the "bypass" to make it entertaining
In the Pillar Pit - Add some chaos orbs as well as the oozes. If chaos orbs won't work - please add shroud blades.
In the end fight - Add one of Harry's [Arraetrikos's] Lieutenants to the end, make him drop an optional chest for more chances as the named loot. You could even randomize which one is in there with the Kobold.
I liked the quest, just needed more spice and less Ooze.