That was a lot of questions.
Attic key is used in the spooky house. The museum is east of the hotel.
The code is in one of the apartments to the west.
One key is: In spooky house.
The other one in Brigantias courtyard.
Are Garrett being over weigh :) You get to the north part in part 2.
Too bad that you have bad experiences.
The thought is to hate the perpetrator, so that you feels satisfied when putting him in the cell or killing him. And the sad fact is, that this is how it is nowadays. Not that Thief takes places in this modern times.
I guess it was better then.
Glad you find something good too :)