How hard is it to put one in (in my situation)?
Swapping a third is easy ...
How bad is it on the tire wear?
It will wear em down faster.
Shall I expect it to chrip / click/ bang?
Yup turning tight corners with traction, one tire will have to slip (causing a chirp). No click or bang.
How is the drivablity in different weather?
Turning on ice can cause the rear to break free (one tire has to slip). Not any worse than a lockrite type tho IMO.
Is it worth even thinking about?
Sure is nice offroad, but "every day in the city" might not be your best choice.