Goldenglow Estate - Completed without any detection.
Honningbrew Meadery - Killed skeevers and a madman
East Empire Trading Company Warehouse - Completely undetected, but killed a dog. It made me sad. Had to keep calming Mercenaries that attacked me while I was talking to Gulum-Ei though, ugh.
Snow Veil Sanctum - Killed the undead remains of ancient Alduin worshippers
Calcelmo's Library - Undetected yet again.
Riftweald Manor - Undetected by the Mercs, persuaded the thug at the gate to let me in by wiping his debt.
Irkgnthand (whatever) - Snuck by Falmer, but had to kill a few.
Twilight Sepulcher - Killed ghosts.
Basically I did it the same way, Only 2 dead, the crazy wizard and the one person you have to kill. That's on the quest's, I haven't done all the radiant quest's to get all the "holds" yet, but I will still try my hardest to not kill anyone with my Thief character.
I did try not to kill the crazy wizard but didn't manage it, I guess my char's sneak skill wasn't high enough at that time.
Their are quest's that you can help people with out killing anyone, quest related, what you run into along the way is another story.
Edit: I have about 550+ hr's on different characters, no mass murder's yet. I haven't done the DB yet, but I expect some murder their...assassin.

