Please don't call the Trentino "South Tirol".
Technically, it's a correct as the entire region was part of Tyrol before WWI.
Yes... for a hundred years... but South Tirol is a pretty welldefined term and is the part of Tirol proper south of the Brenner. Ie not the princebishopric of Trento.
For instance the treaty of 1915 (between Italy and the Entente) refers to "the Trentino and Cisalpine Tyrol".
Do you call it Bozen or Bolzano? Most of my relatives always called in Bozen when I talked to them.
I guess I'd use Bolzano when speaking English. Certainly not when speaking German though, that'd be pretty silly. I
tend to use the Polish or Czech names when speaking of a place in
formerly German speaking territory (when speaking about the place as it is now, that is) but that's something else. South Tirol is a German speaking region after all, and one where German is used in local administration.