When I get to this place it shows a marker arrow and it leads you to an upper floor which takes you to a grate (door) which leads you back (big fall) down to the entrance. Anyone know if there is some really simple thing I am missing? I cannot locate this leader and Clairvoyance spell just leads me around in circles.

The leader should be there in that room with the grate on the floor. Maybe you got bugged out?

I have trouble finishing this returning to Farkas. I got back to him, but when I talk to him, I can't finish the quest, and if I ask him for work, he says I am doing soemthing for Aela, which of couse, I am not. Is there some console command to force the quest to end or something?

I found the command to end this
setstage CR05 200

Marked it as finished, and I could talk to the companion leaders and get a new quest