And how autofocus works in nigth? Fast, slow or dont work?
If you are focusing on a subject that has a little light and some contrast, there is no problem. It works very quickly.
If not, pop up the flash, let the auto-focus assist do it's job (it will work in pitch blackness), get your focus, switch to manual focus, close the flash unit, make your exposure adjustments, and take the shot. Works like a charm.
PS. I LOVE this camera. I have yet to hear an owner say they are not satisfied with the results.
I like your venice shots in term of colors and 'mood'.
Just as a comment I think they are a little too much 'centered' and would have had more strength with a different composition. Except if it is by 'choice' and you were trying to express something specific.