Genealogy /
I am 1/8 Polish on my mother's side - not Polish enough / Lithuania and Zmudz in Poland's ancestry [110]
As to Litwa it had such name in difference with Crown (Poland) even after Lublin Union.Until 1795 Litwins didn't call themselves Poles.Now Litwa is apart from Poland. Two states Belarus and Litvania occupy its territory. That's the reason why I think My ancestors were from Litwa not for Poland despite speaking Polish
You seems to be intelligent and well educated person, but IMO in this case, you are mixing several things and don't understand some. Compare Polish community in Kresy (now western Ukraine, Belarus and Lithuania) to German one on former German land (now western Poland). Germans living there were Germans, similarly Poles living in the Kresy were Poles. They called themselves Poles, spoke Polish, were held within Polish culture, had Polish parents, etc.... After hundreds of years of Polish-Lithuanian Commonwealth Poles were emigrating in the east and this fact didn't make Lithuanians of them.
About Mickiewicz: for me he did more bad things to Poles that good, so if Lithuanians want to take him, let them do it :D. We had more noble Poles and it's better to look among mathematicians and engineers rather than poets.
About you: YES, some of your ancestors were Polish (I know it hurts in contemporary Putin-rulled Russia). Remember not to tell it to anybody, it's dangerous for your teeth ;).