To know whether playing cards would be acceptable in a culture or not, we need to understand and be thorough with the general cultures in the world. Primarily, though there are lots of countries (obviously) there are only a fixed number of GENERAL cultures. By this I mean (examples --> ) that the cultures of India and Pakistan or the different countries in Europe (with a few exceptions though) are vastly the same, just like the GENERAL culture of Canada and the United States would be the same.
Of course there are very significant differences, but for our understanding and ensuring that playing cards (and other such items which might have negative connotations) are welcome or not, these GENERAL cultures will do.
The culture of the Indian Subcontinent is very traditional. However, cards here have been accepted as something to do magic with, too. Hence they'll be welcome here, I'm sure it won't be a worry, unless you deliberately go to poor localities where cards have brought about large-scale destructions in families and the local economy (refer to Sean O's cardistry documentary on YouTube, it was shot in Nepal).
But yes, sizes of the cards do differ. If you come to Asia, don't be surprised if people find your cards a bit too big, because the Bridge size is the norm here (which is why those people who keep saying that magicians and cardists who practice with Bridge sized are doing the wrong, weird thing, I politely call them ''minorly ignorant'').
But that isn't a huge problem. I don't think playing cards are too unwelcome anywhere now-a-days (with the exception I mentioned above).
Just be sure to not look too seedy, and nobody will mistake you as somebody anti-social.
PS:- Your questions and this thread are really interesting. I can't help wonder... Is this just curiosity on your part or are you really planning a World Tour?
