Konitski: 
According to the 1804 Code Napoléon in vigor at the time of Chopin's birth, Chopin was born a Frenchman - now, whether you want to interpret this as a French national or a French citizen, as far as I am concerned, c'est du pareil au même: he was a Frenchman.
Chopin began travelling outside of Poland - or should we say the Duchy of Warsaw? - in 1828: Berlin; 1829, Vienna, Prague, Dresden; 1830: Dresden, Prague, Vienna; 1831: Vienna, Stuttgart, Paris. In order to travel, he needed a passport and I assume (forgive me Widipedia for assuming) that he travelled on a Polish or Duchy of Warsaw passport.  No, I have no facsimile of it, nor have I ever seen any, but without passport, Chopin could not have left Poland. 
NOTE: In Selected Correspondence of Fryderik Chopin, collected & annotated by Bornislaw Edward Sydow, translated from Polish and other languages Chopin was using in his correspondence, by Arthur Hedley, McGraw-Hill, 1963, p. 90, from what is referred to as Chopin's Album: 
Stuttgart, after 8 September 1831: "My passport expires next month - I am not entitled to live in a foreign country - at least I have no official right..."