I think i misread this when I woke up. You have to click the fly action first (you get this action from illithid powers, grant flight spell, or potion of flying), then click to where you want to move. Don’t click outside the giant circle or youll start walking first and that will use up some movement of flight. You can see how much movement you have left by looking at the bottom of your screen and that little yellow line is the amount of movement you have left relative to your maximum movement. Also if you have everyone use the astral touched tadpole they will get flight for free so you can have your whole squad flying if you pass a few persuasion/intimidation checks.
Technically omeluum the mind flayer from the underdark is back there too if you did his quests but he can teleport.
But no there is just the lady in the chair and the dwarf lady (maybe halfling) locked in a cell in that room. There are two door levers to close the doors but they are one for each door. One is just outside the room with the respawning sahuagin and the other is on the opposite end of that corridor. You can’t really use that one to lock them out though since you’d be on the wrong side of the door.
I love optimizing my route through the iron throne. I’ve done it like 8 or 9 times now. If you have flying it makes the entire place a joke. Basically fly to everyone turn one, free everyone turn two, and escape on turn three.