Well, apart from John Godson, how many non-POLES serve or have ever served in the Sejm? How many professing Jews?
Not many professing Jews (has there been any in the 3rd Republic?), though some had Jewish origins. There's a chap from Zambia in the current Sejm who is a decent guy as well, and there's always at least one member of the German minority in the Sejm. I think there's been some from other national minorities as well.
there is enough Jews in public life in Poland, don't you worry - they are by far overrepresented there
Not really. Some might be the children/grandchildren of secular Jews, but they are Polish first and foremost.