On the second issue, I think seating arrangements/general proximity are exactly why Aginor and Baalthamel were closer to the surface of the Bore. We know that they weren't currently among the top of the DO's minions. Neither had governed well, nor were they exceptional generals. They were simply selfish, devious, and strong enough, to outlast their competition.

So, they were likely seated far from the presence of the DO, however that manifested. Those who governed well, were useful to the true leaders, or who were currently serving as governors were closer.

Just my thoughts.