Great rooftop mission and I suspect I didn't find anywhere. I got the loot objective on Difficult but that was only 3/4ths of all the loot available so I missed a lot.
It might be me but the AI seemed more sensitive and most everywhere on roofs and ledges, unless I crept (which takes forever) I aroused low level suspicion. I gave up trying too hard to have no suspicions but even so, the stats showed 108 low level suspicions so I reckon some I never even heard or saw. Perhaps it was the context of being out in a city at night and a tiny scratch on metal aroused a guard way in the distance seemed a bit unnatural. Close to, I expect to occasionally have creep on metal past a guard at a desk a couple of paces away, but to have to do it 3/4ths of the time with guards out of sight way down in and along a street got a bit wearing. So, I don't know if it was intended but, just saying.
Good idea to repeat some of the readable info to help reinforce the story so I did feel I was in a story even though I doubt I absorbed it all.
Overall, very enjoyable except the (apparently) over-sensitive enemy was a mild irritation here and there until I eased off trying to ghost it perfectly. BTW I don't think I used any tools etc except the one rope I kept reusing. I had tons of stuff at the end. Not sure about moss. There were one or two places I'd like to have used moss but I only had one at that time and had to save it in case there was an impossible place where it was needed later. Maybe that's one answer - add a dozen moss at the start and a hint to use them. The sensitivity would then add to the fun instead of taking away.