Lou: Spellcraft DC to identify a spell being cast is 15+spell level, so 16. I see nothing in Pathfinder rules about +1 DC per each 10 feet of distance from the caster. As long as you can see/hear him, you're good to go. There may be a penatly to the check if you can't both see and hear the caster.
Yttermayn: No, you were all shown in by different footmen/butlers, one of whom led each group in and then left.
All: So you've seen three different footmen, plus the two stationed outside the door to this chamber bearing long ranseurs. As the group stands or sits in curiosity, you begin to hear the faint sound of rhythmic chanting coming from somewhere deeper in the temple.
[OOC: Any who speak Oeridian recognize the language of the chant as being an ancient form of that language. The words are a bit hard to follow, and you can't hear them all that clearly yet, but it sems to be something about blessings and trials and grace and adversity.]
[OOC: For any who do not know, the human tongues spoken in the Flanaess are Suel, Baklunish, Oeridian, and Flan. And common, of course, which is a blend of mostly Oeridian and Flan. That last bit about common is not from any Greyhawk publication, that's just me, and any contradiction or similarity to any actual Greyhawk doctrine is purely coincidental. Regardless, my ruling is my ruling.]