Weapon aggro range varies by time of day too though, during the day I could easily run through Ro'Maeve as rng/nin (alertness/stealth) without any aggro at all, unless I actually came into physical contact with a weapon. At night I would aggro from a couple steps away.
Statues have blinders on. They see straight ahead for about 5 steps, and that's it. When they turn they can make sharp turns, and while you would think they would see someone in between their original line of sight and their new line of sight during the rotation, they don't.
For example, the statue is facing north, you're northeast of it. It starts walking east, rotating past you, appearing to look at you in the process. It wouldn't see you.