What's totally missing: Inform yourself where/when you are allowed to take pictures and what you are allowed to do with them afterwards. Helps both to affirm yourself that what you are doing is ok and to not look totally clueless if challenged. (but don't be an ass about "but it is my RIGHT", either) And repeat that process when traveling, with added emphasis on cultural aspects.
Here in Norway it is allowed to take photos in public of groups of people without asking but it is not allowed to single out a person in specific and take their photo without permission. I think cropping a photo to produce a portrait would also fall under the latter btw.
So yes, it's absolutely important to be aware of local laws.